## 1. Introduction and History



The idea that our actual moral judgments are an important source of
information about the origins and justification of moral norms goes
back to ancient Greece, if not further. Herodotus recounts a story in
which the Persian emperor Darius invited Greek members of his court
"and asked them what price would persuade them to eat the dead
bodies of their fathers. They answered that there was no price for
which they would do it." Darius then summoned members of a
different group, "and asked them... what would make them
willing to burn their fathers at death. The Indians cried aloud, that
he should not speak of so horrid an act." Herodotus concludes
that stories like these prove that, as the poet Pindar writes,
"custom is king of all," thereby providing an instance of
the argument from moral disagreement for relativism. Likewise, in the
*Outlines of Skepticism*, Sextus Empiricus stresses that
empirical discoveries can destabilize our confidence in universal
moral agreement:



> 
> even if in some cases we cannot see an anomaly, we should say that
> possibly there is dispute about these matters too... Just as, if
> we had not, for example, known about the Egyptian custom of marrying
> their sisters, we should have affirmed, wrongly, that it is agreed by
> all that you must not marry your sister. (Sextus Empiricus,
> *Outlines of Skepticism*)
> 



While the use of empirical observation in moral theory has a long
history, the contemporary movement known as experimental philosophy
goes back only a few decades. The current experimental philosophy
movement owes its beginnings to the work of Stephen Stich, Shaun
Nichols and Jonathan Weinberg (2001) and Joshua Knobe (2003), but
the earliest instance of experimental philosophy may be *Truth as
Conceived by Those Who Are Not Professional Philosophers* (Naess
1938), which surveyed ordinary speakers for their intuitions about the
nature of truth. Contemporary philosophers have not been uniformly
accepting of the movement, but as we will see, there are reasons to
think that experimental evidence might have a distinctive role,
significance, and importance in moral philosophy and theorizing.



The relationship between more traditional philosophy and experimental
work is instructive and brings out some tensions within moral
philosophy and theory: namely, morality is at once practical and
normative, and these two aspects inform and constrain the extent to
which it is accountable to human psychology.



Insofar as morality is practical, it should be accessible to and
attainable by agents like us: if a theory is too demanding, or relies
on intuitions, judgments, motivations, or capacities that people do
not (or, worse, cannot) possess, we might on those grounds dismiss it.
On the other hand, morality is also normative: it aims not just to
describe what we actually do or think, but to guide our practice. For
this reason, some philosophers have responded to experimental results
claiming to show that attaining and reliably expressing virtues in a
wide variety of situations is difficult (see section 3.1 below for a
discussion of this literature) by pointing out that the fact that
people do not always make the right judgment, or perform actions for
the right reasons, does not falsify a theory--it simply shows
that people often act in ways that are morally deficient. We will
return to these issues when we discuss criticisms of experimental
moral philosophy at the end of this entry; for now, we mention them to
illustrate that the extent to which experimental moral philosophy
challenges traditional philosophical approaches is itself a
controversial issue. Some moral philosophers see themselves as
deriving moral principles a priori, without appeal to contingent facts
about human psychology. Others see themselves as working within a
tradition, going back at least as far as Aristotle, that conceives of
ethics as the study of human flourishing. These philosophers have not
necessarily embraced experimental moral philosophy, but many
practitioners envision their projects as outgrowths of the
naturalistic moral theories developed by Aristotle, Hume, and
others.


### 1.1 What Are Experiments?



As the examples discussed above reveal, a variety of types of
empirical evidence are useful to moral theorizing (see also the
entries on empirical moral psychology, empirical distributive justice,
and empirical psychology and character). Anthropological observation
and data have long played a role in moral philosophy. The
twentieth-century moral philosophers John Ladd and Richard Brandt
investigated moral relativism in part by conducting their own
ethnographies in Native American communities. Brandt writes, "We
have... a question affecting the truth of ethical relativism
which, conceivably, anthropology can help us settle. Does ethnological
evidence support the view that "qualified persons" can
disagree in ethical attitude?" But, he notes, "some kinds
of anthropological material will not help us--in particular, bare
information about intercultural differences in ethical opinion or
attitude." (1952: 238). This is a caveat frequently cited by
philosophers engaged in empirical research: it is important to have
philosophers participate in experimental design and the gathering of
empirical data, because there are certain questions that must be
addressed for the data to have philosophical applications--in
this case, whether moral disagreements involve different factual
beliefs or other non-moral differences. Barry Hallen (1986, 2000)
conducted a series of interviews and ethnographies among the Yoruba,
investigating central evaluative concepts and language relating to
epistemology, aesthetics, and moral value. Hallen was motivated by
questions about the indeterminacy of translation, but his work
provides an example of how in-depth interviews can inform
investigations of philosophical concepts.



These examples show that ethnography has a valuable role to play in
philosophical theory, but the remainder of this entry will focus
primarily on experiments. Paradigmatic experiments involve randomized
assignment to varying conditions of objects or people from a random
sample, followed by statistical comparison of the outcomes for each
condition. The variation in conditions is sometimes called a
manipulation. For example, an experimenter might select a random
sample of people, randomly assign them either to find or not to find a
dime in the coin return of a pay phone, and then measure the degree to
which they subsequently help someone they take to be in need (Isen
& Levin 1972). Finding or not finding the dime is the condition;
degree of helpfulness is the outcome variable.



While true experiments follow this procedure, other types of studies
allow non-random assignment to conditions. Astronomers, for example,
sometimes speak of natural experiments. Although we are in no position
to affect the motions of heavenly bodies, we can observe them under a
variety of conditions, over long periods of time, and with a variety
of instruments. Likewise, anthropological investigation of different
cultures' moral beliefs and practices is unlikely to involve
manipulating variables in the lives of the members of the culture, but
such studies are valuable and empirically respectable. Still,
inferring causation is more difficult with such studies, so the
evidential value of these studies is often less than that of
experiments, at least in this respect; most published research in
experimental philosophy involves true experiments.



Even within the category of experiments, we find a lot of diversity
with respect to inputs, methods of measurement, and outputs. The
experiment just described uses a behavioral measure and
manipulation--finding the dime is the input, helping is the
outcome measured. Other experiments measure not behavior but judgment
or intuition, and this can be done using a survey or other form of
self-report or informant-report where subjects respond
explicitly to some question, situation, or dilemma. Studies measuring
judgments might use either manipulations of the condition in which the
subject makes the judgment, or they might look for correlations
between judgments and some other factor, such as brain activity,
emotional response, reaction time, visual attention, and so on
(Strohminger et al. 2014).



The experimental methods available have also changed over time.
Surveys have been the dominant method of experimental philosophy for
the past few decades, but technology may change this: advances in
virtual and augmented reality mean that philosophers can now immerse
people in moral dilemmas such as Thompson's (1971) violinist
thought experiment and different versions of the trolley problem
(e.g., Navarrete et al 2012). Philosophers interested in the neural
correlates of moral judgment can use transcranial magnetic stimulation
(TMS) to investigate the effects of enhancing or lessening activity in
certain areas of the brain. Even survey methods have seen advances
thanks to technology; the ubiquity of smartphones allows researchers
to ping people in real time, asking for reports on mood (see section
3.2 below for a discussion of surveys relating to happiness and
mood).



Whether experimental moral philosophy has to use true experiments or
can include studies and even ethnographies and other forms of
qualitative data is partly a terminological question about how to
define the field and whether we distinguish it from empirical moral
psychology, a closely related research program. As we will see below,
though, a diversity of both methods and subjects is important in
helping experimental moral philosophy respond to its critics.


### 1.2 What Types of Questions and Data?



Like experimental philosophy more generally, experimental moral
philosophy is interested in our intuitions and judgments about
philosophical thought experiments and moral dilemmas. But research in
this area also concerns the cognitive architecture underlying our
moral judgments; the developmental processes that give rise to moral
judgments; the neuroscience of moral judgment; and other related
fields.



*Direct* experiments investigate whether a claim held (or
denied) by philosophers is corroborated or falsified. This might mean
investigating an intuition and whether it is as widely shared as
philosophers claim, or it might mean investigating the claim that a
certain behavior or trait is widespread or that two factors covary.
For example, we find philosophers claiming that it is wrong to
imprison an innocent person to prevent rioting; that a good life must
be authentic; and that moral judgments are intrinsically motivating.
Experimental research can be (and has been, as we will see below)
brought to bear on each of these claims.



*Indirect* experiments look at the nature of some capacity or
judgment: for example, whether certain types of moral dilemmas engage
particular areas of the brain; how early children develop a capacity
to empathize; and whether the moral/conventional distinction is
universal across cultures (for discussion of the moral/conventional
distinction, see Machery & Stich 2022). These claims have
philosophical relevance insofar as they help us understand the nature
of moral judgment.



In addition to distinctions involving the type of data and how
directly it bears on the question, we can also distinguish among
experimental applied ethics, experimental normative ethics, and
experimental metaethics. The first involves the variables that
influence judgments about particular practical problems, such as how a
self-driving car should respond to sacrificial dilemmas (Bonnefon,
Sharriff & Rahwan 2016). The second involves investigations
of how we ought to behave, act, and judge, as well as our intuitions
about moral responsibility, character, and what constitutes a good
life. The third involves debates over moral realism and antirealism.
In this entry we focus on the latter two.



In many of these cases, the line between experimental moral philosophy
and its neighbors is difficult to draw: what distinguishes
experimental moral philosophy from empirical moral psychology? What is
the difference between experimental moral philosophy and psychology or
neuroscience that investigates morality? What is the difference
between experimental moral philosophy and metaethics? We might try to
answer these questions by pointing to the training of the
experimenters--as philosophers or as scientists--but much of
the work in these areas is done by collaborative teams involving both
philosophers and social scientists or neuroscientists. In addition,
some philosophers work in law and psychology departments, and graduate
programs increasingly offer cross-disciplinary training. Another
approach would be to look at the literature with which the work
engages: many psychologists (e.g., Haidt, Greene) investigating moral
judgment situate their arguments within the debate between Kantians
and Humeans, so engagement with the philosophical tradition might be
used as a criterion to distinguish experimental moral philosophy from
experimental moral psychology. All this said, an inability to sharply
distinguish experimental moral philosophy from adjoining areas of
investigation may not be particularly important. Experimental
philosophers often point out that the disciplinary divide between
philosophy and psychology is a relatively recent phenomenon; early
twentieth-century writers such as William James situated themselves in
both disciplines, making vital contributions to each. If there is a
problem here, it is not unique to experimental moral philosophy. For
example, is work on semantics that uses both linguistics and analytic
philosophy best understood as linguistics or philosophy of language?
These debates arise, and may be largely moot, for many research
programs that cut across disciplinary boundaries.



The rest of this entry proceeds as follows. Section 2 canvasses
experimental research on moral judgments and intuitions, describing
various programmatic uses to which experimental results have been put,
then turning to examples of experimental research on moral judgment
and intuition, including intuitions about intentionality and
responsibility, the so-called linguistic analogy, and some
cross-cultural work. Section 3 discusses experimental results on thick
(i.e., simultaneously descriptive and normative) topics, including
character and virtue, well-being, emotion and affect, and moral
standing. Section 4 discusses questions about moral disagreement and
moral language, both important sources of evidence in the longstanding
debate over moral objectivity. Section 5 considers some objections to
experimental moral philosophy.


## 2. Moral Intuitions and Conceptual Analysis



One role for experiments in moral philosophy, as indicated above, is
to investigate our moral intuitions about cases, and to use the
results gleaned from such investigations to guide or constrain our
moral metaphysics, semantics, or epistemology. Philosophers often rely
on such judgments--in the form of claims to the effect that
"we would judge x" or, "intuitively,
x"--as data or evidence for a theory (though see Cappelen
2012, Deutsch 2016, and Machery 2017 for critical discussion of this
point). Claims about what we would judge or about the intuitive
response to a case are empirically testable, and one project in
experimental moral philosophy (perhaps the dominant original project)
has been to test such claims via an investigation of our intuitions
and related moral judgments. In doing so, experimental moral
philosophers can accomplish one of two things: first, they can test
the claims of traditional philosophers about what is or is not
intuitive; second, they can investigate the sources of our intuitions
and judgments. These tasks can be undertaken as part of a positive
program, which uses our intuitions and judgments as inputs and
constructs theories that accommodate and explain them. Alternatively,
these tasks can figure in a negative program, which uses experimental
research to undermine traditional appeals to intuition as evidence in
moral philosophy and conceptual analysis more broadly. The negative
program can proceed directly or indirectly: either via testing and
refuting claims about intuitions themselves, or by discrediting the
sources of those intuitions by discovering that they are influenced by
factors widely regarded as not evidential or unreliable. We discuss
both the negative program and the positive program below.


### 2.1 The Negative Program in Experimental Moral Philosophy



Early work in experimental philosophy suggested cross-cultural
differences in semantic, epistemic, and moral intuitions. For example,
Machery, Mallon, Nichols, and Stich (2004) argued that East Asian
subjects were more likely to hold descriptivist intuitions than their
Western counterparts, who tended to embrace causal theories of
reference. Haidt (2006) argued that the extent to which people judged
harmless violations such as eating a deceased pet, or engaging in
consensual sibling incest, to be wrong depended on socioeconomic
status. Since, presumably, moral wrongness doesn't itself depend
on socioeconomic status, gender, or culture of the person making the
moral judgment, these results have been marshaled to argue either
against the evidential value of intuitions or against the existence of
moral facts altogether.



Negative experimental moral philosophy generates results that are then
used to discount the evidential value of appeals to intuition (for
review, Machery 2017, Chapter 2). For example, Singer (2005),
Sinnott-Armstrong (2008d), Lanteri and colleagues (2008), Lombrozo
(2009), Schwitzgebel and Cushman (2012, 2015), Liao and colleagues
(2012), Tobia and colleagues (2013), Wiegmann and colleagues (2020),
Rehren and Walter (2021), and McDonald et al. (2021) have
argued that moral intuitions are subject to normatively
irrelevant situational influences (e.g., order or framing effects),
while Feltz and Cokely (2009) and Knobe (2011) have documented
correlations between moral intuitions and (presumably) normatively
irrelevant individual differences (e.g., extroversion). Such results
might warrant skepticism about moral intuitions, or at least about
some classes of intuitions or
 intuiters.[1]



The studies just mentioned involve results that suggest that the
content of intuitions varies along some normatively irrelevant
dimension. Another source of evidence for the negative program draws
on results regarding the cognitive mechanisms underlying or generating
intuitions themselves. For example, studies that suggest that
deontological intuitions are driven by emotional aversions to harming
others have been used to argue that we ought to discount our
deontological intuitions in favor of consequentialist
principles--an idea discussed in more detail below (see Singer
2005; Wiegman 2017). In several experiments, Kneer and
Machery (2019) show that judgments about moral luck result from
the hindsight bias, i.e., the tendency to overestimate the probability
that events known to have happened would happen. Thus, the
probability that the unlucky event in a bad luck situation (e.g.,
a car accident involving a drunk driver) would happen is
overestimated and the agent is judged to have been more
negligent than her counterpart in a lucky situation (the drunk
driver who did not get into any accident). This psychological account
is then used to undermine the philosophical significance of intuitions
about moral luck: If the asymmetry between good and back luck
situations is due to a psychological bias, it should not bear on
philosophical theorizing.



The distinction between negative and positive experimental moral
philosophy is difficult to draw, partly because the negative program
often discounts particular classes or types of intuitions in favor of
others that are supposed to be more reliable. For example, Singer
offers an anti-deontological argument as part of the negative program
insofar as his argument uses the emotional origins of deontological
intuitions to discount them. But because he then argues for the
superiority of consequentialist intuitions, his position also fits
within the positive program. So the difference between the two
programs is not in the data or the kinds of questions investigated,
but in how the data are put to use--whether they are seen as
debunking traditional philosophical appeals to intuition or as an
addition to traditional philosophical appeals to intuition, by helping
philosophers distinguish between reliable and unreliable intuitions
and their sources. In the next section, we look at positive uses of
intuitions as evidence.


### 2.2 The Positive Program in Experimental Moral Philosophy



Other philosophers are more sanguine about the upshot of experimental
investigations of moral judgment and intuition. Knobe, for example,
uses experimental investigations of the determinants of moral
judgments to identify the contours of philosophically resonant
concepts and the mechanisms or processes that underlie moral judgment.
He has argued for the pervasive influence of moral considerations
throughout folk psychological concepts (2009, 2010; see also Pettit
& Knobe 2009), claiming, among other things, that the concept of
an intentional action is sensitive to the foreseeable evaluative
valence of the consequences of that action (2003, 2004b,
 2006).[2]




Another line of research is due to Joshua Greene and his colleagues
(Greene et al. 2001, 2004, 2008; Greene 2008), who investigate the
neural bases of consequentialist and deontological moral judgments
(but see Kahane et al. 2015). Greene and his colleagues elicited the
intuitions of subjects about a variety of trolley problems--cases
that present a dilemma in which a trolley is racing towards five
individuals, all of whom will be killed unless the trolley is instead
diverted towards one individual--while inside an fMRI scanner.
The researchers found that, when given cases in which the trolley is
diverted by pulling a switch, most subjects agreed that diverting the
trolley away from the five and towards the one person was the right
action. When, instead, the case involved pushing a person off a bridge
to land in front of and halt the trolley, subjects were less likely to
judge that sacrificing the one person as morally permissible. In
addition, Greene found that subjects who did judge it permissible to
push the person took longer to arrive at their judgment, suggesting
that they had to overcome conflicting intuitions to do so (but see
McGuire et al. 2009)--a finding bolstered by the fact that when
subjects considered pushing the person off the bridge, their brains
revealed increased activity in areas associated with the aggregation
and modulation of value signals (e.g., ventromedial prefrontal cortex
and dorsolateral prefrontal cortex). Greene concludes that our
aversion to pushing the person is due to an emotional response to the
thought of causing physical harm to someone, while our willingness to
pull the switch is due to the rational calculation that saving five
people is preferable to letting five people die to spare one life.
Greene and Singer use these findings as a basis for a debunking of
deontological intuitions and a vindication of consequentialism, since
the latter rests on intuitions which stem from a source we consider
both generally reliable and appropriately used as the basis for moral
reasoning. It should be noted, though, that this argument presupposes
that emotional reactions are (at least in these cases) necessarily
irrational or arational; philosophers who are unsympathetic to such a
view of emotions need not follow Greene and Singer to their ultimate
conclusions (Berker 2009; Greene 2014; Railton 2014).



A related approach aims to identify the features to which intuitions
about philosophically important concepts are sensitive. Sripada (2011)
thinks that the proper role of experimental investigations of moral
intuitions is not to identify the mechanisms underlying moral
intuitions. Such knowledge, it is claimed, contributes little of
relevance to philosophical theorizing. It is rather to investigate, on
a case by case basis, the features to which people are responding when
they have such intuitions. On this view, people (philosophers
included) can readily identify whether they have a given intuition,
but not why they have it. An example from the debate over determinism
and free will: manipulation cases have been thought to undermine
compatibilist intuitions--intuition supporting the notion that
determinism is compatible with "the sort of free will required
for moral responsibility" (Pereboom 2001). In such cases, an
unwitting victim is described as having been surreptitiously
manipulated into having and reflectively endorsing a motivation to
perform some action. Critics of compatibilism say that such cases
satisfy compatibilist criteria for moral responsibility, and yet,
intuitively, the actors are not morally responsible (Pereboom 2001).
Sripada (2011) makes a strong case, however, through both mediation
analysis and structural equation modeling, that to the extent that
people feel the manipulee not to be morally responsible, they do so
because they judge him in fact not to satisfy the compatibilist
 criteria.[3]
 Thus, by determining which aspects of the case philosophical
intuitions are responding to, it might be possible to resolve
otherwise intractable questions.


### 2.3 An Example: Intentionality and Responsibility



Since Knobe's seminal (2003) paper, experimental philosophers
have investigated the complex patterns in people's dispositions
to make judgments about moral notions (praiseworthiness,
blameworthiness, responsibility), cognitive attitudes (belief,
knowledge, remembering), motivational attitudes (desire, favor,
advocacy), and character traits (compassion, callousness) in the
context of violations of and conformity to various norms (moral,
prudential, aesthetic, legal, conventional,
 descriptive).[4]
 In Knobe's original experiment, participants first read a
description of a choice scenario: the protagonist is presented with a
potential policy (aimed at increasing profits) that would result in a
side effect (either harming or helping the environment). Next, the
protagonist explicitly disavows caring about the side effect, and
chooses to go ahead with the policy. The policy results as advertised:
both the primary and the side effect occur. Participants are asked to
attribute intentionality or an attitude (or, in the case of later work
by Robinson et al. 2013, a character trait) to the protagonist. What
Knobe found was that participants were significantly more inclined to
indicate that the protagonist had intentionally brought about the side
effect when it was perceived to be bad (harming the environment) than
when it was perceived to be good (helping the environment). This
effect has been replicated dozens of times, and its scope has been
greatly expanded from intentionality attributions after violations of
a moral norm to attributions of diverse properties after violations of
a wide variety of norms.



The first-order aim of interpreters of this body of evidence is to
create a model that predicts when the attribution asymmetry will crop
up. The second-order aims are to explain as systematically as possible
why the effect occurs, and to determine the extent to which the
attribution asymmetry can be considered rational. Figure 1, presented
here for the first time, models how participants' responses to
this sort of vignette are produced (for a different, neuroscientific
approach, see Ngo et al. 2015):



![diagram of participant response](fig1.png)

Figure 1. Model of Participant Response
to Experimental Philosophy Vignettes




In this model, the boxes represent constructs, the arrows represent
causal or functional influences, and the area in grey represents the
mind of the participant, which is not directly observable but is the
target of investigation. In broad strokes, the idea is that a
participant first reads the text of the vignette and forms a mental
model of what happens in the story. On the basis of this model (and
almost certainly while the vignette is still being read), the
participant begins to interpret, i.e., to make both descriptive and
normative judgments about the scenario, especially about the mental
states and character traits of the people in it. The participant then
reads the experimenter's question, forms a mental model of what
is being asked, and--based on her judgments about the
scenario--forms an answer to that question. That answer may then
be pragmatically revised (to avoid unwanted implications, to bring it
more into accord with what the participant thinks the experimenter
wants to hear, etc.) and is finally recorded as an explicit response
to a statement about the protagonist's attitudes (e.g.,
"he brought about the side effect intentionally," graded
on a Likert
 scale).[5]



A result that has been replicated repeatedly is that, when the
vignette describes a norm violation, subjects indicate that they agree
more strongly that the action violating the norm was performed
intentionally. While this finding could be used by proponents of the
negative program to undermine the conceptual coherence of our notion
of moral responsibility, experimental moral philosophers working in
the positive program have taken up the task of explaining the
asymmetry by postulating models of unobservable entities that mediate,
explain, and perhaps even rationalize the asymmetry. A discussion of
several attempts to do so follows; each offers a different explanation
of the asymmetry, but all represent vindications or at least
rehabilitations of our intuitions about intention.



*The Conceptual Competence Model*



Perhaps the best known is Knobe's conceptual competence model,
according to which the asymmetry arises at the judgment stage. On this
view, normative judgments about the action influence otherwise
descriptive judgments about whether it was intentional (or desired, or
expected, etc.). Moreover, this influence is taken to be part of the
very conception of intentionality (desire, belief, etc.). Thus, on the
conceptual competence model, the asymmetry in attributions is a
rational expression of the ordinary conception of intentionality
(desire, belief, etc.), which turns out to have a normative component
(see Machery 2008 for doubts about how to circumscribe what is part of
the conceptual competence with any given
 concept).[6]



*The Motivational Bias Model*



The motivational bias model (Alicke 2008; Nadelhoffer 2004, 2006)
agrees that the asymmetry originates in the judgment stage, and that
normative judgments influence descriptive judgments. However, unlike
the conceptual competence model, it takes this to be a bias rather
than an expression of conceptual competence. Thus, on this model, the
asymmetry in attributions is a distortion of the correct conception of
intentionality (desire, belief, etc.).



*The Deep Self Model*



The deep self concordance model (Sripada 2010, 2012; Sripada &
Konrath 2011) also locates the source of the asymmetry in the judgment
stage, but does not recognize an influence (licit or illicit) of
normative judgments on descriptive judgments. Instead, proponents of
this model claim that when assessing intentional action, people not
only attend to their representation of a person's
"surface" self--her expectations, means-end beliefs,
moment-to-moment intentions, and conditional desires--but also to
their representation of the person's "deep" self,
which harbors her sentiments, values, and core principles (for
critical discussion, see Rose et al. 2012). According to this model,
when assessing whether someone intentionally brings about some state
of affairs, people determine (typically unconsciously) whether there
exists sufficient concordance between their representation of the
outcome the agent brings about and what they take to be her deep self.
For instance, when the chairman says he does not care at all about
either harming or helping the environment, people attribute to him a
deeply anti-environment stance. When he harms the environment, this is
concordant with his anti-environment deep self; in contrast, when the
chairman helps the environment, this is discordant with his
anti-environment deep self. According to the deep self concordance
model, then, the asymmetry in attributions is a reasonable expression
of the folk psychological distinction between the deep and shallow
self.



*The Conversational Pragmatics Model*



Unlike the models discussed so far, the conversational pragmatics
model (Adams & Steadman 2004, 2007; Lindauer & Southwood 2021)
locates the source of the asymmetry in the pragmatic revision stage.
According to this model, participants judge the protagonist not to
have acted intentionally in both norm-conforming and norm-violating
cases. However, when it comes time to tell the experimenter what they
think, participants do not want to be taken as suggesting that the
harm-causing protagonist is blameless, so they report that he acted
intentionally. This is a reasonable goal, so according to the
pragmatic revision model, the attribution asymmetry is rational,
though misleading.



*The Trade-Off Model*



The trade-off model (Machery 2008) disagrees with the previous models
about the location of the source of the asymmetry: it locates it in
the interpretation of the scenario. It proposes that when people
read that the chairman agrees to harm the environment, they
conceptualize the side effect *harming the
environment* as a cost, that is, as something that is
negatively valued and that one must incur if one is to reap a greater
benefit. People think of this cost as being offset by the
benefit *increasing the profits of the company*. That is,
they conceptualize the harm case as involving a trade-off between a
cost and a benefit. The side effect *helping the
environment* cannot be conceptualized in this way since
it cannot be plausibly thought of as a cost. Since people think of
costs as being intentionally incurred in order to reap some foreseen
benefits, the side effect is judged to be intentional in the former
situation, but not in the latter situation. 



*The Deliberation Model*



Like the trade-off model, according to the deliberation model (Alfano,
Beebe, & Robinson 2012; Robinson, Stey, & Alfano 2013; Scaife
& Webber 2013), the best explanation of the complex patterns of
evidence is that the very first mental stage, the formation of a
mental model of the scenario, differs between norm-violation and
norm-conformity vignettes. When the protagonist is told that a policy
he would ordinarily want to pursue violates a norm, he acquires a
reason to deliberate further about what to do; in contrast, when the
protagonist is told that the policy conforms to some norm, he acquires
no such reason. Participants tend to think of the protagonist as
deliberating about what to do when and only when a norm would be
violated. Since deliberation leads to the formation of other mental
states such as beliefs, desires, and intentions, this basal difference
between participants' models of what happens in the story flows
through the rest of their interpretation and leads to the attribution
asymmetry. On the deliberation model, then, the attribution asymmetry
originates earlier than other experimental philosophers suppose, and
is due to rational processes.


### 2.4 Another Example: The Linguistic Analogy



Another positive program investigates the structure and form of moral
intuitions, in addition to their content, with the aim of using these
features to inform a theory of the cognitive structures underlying
moral judgment and their etiology.



Rawls (1971), drawing on Chomsky's (1965) theory of generative
linguistics, suggested that moral cognition might be usefully modeled
on our language faculty, a parallel endorsed by Chomsky himself:



> 
> I don't doubt that we have a natural moral sense....That
> is, just as people somehow can construct an extraordinarily rich
> system of knowledge of language on the basis of rather limited and
> degenerate experience, similarly, people develop implicit systems of
> moral evaluation, which are more or less uniform from person to
> person. There are differences, and the differences are interesting,
> but over quite a substantial range we tend to make comparable
> judgments, and we do it, it would appear, in quite intricate and
> delicate ways involving new cases and agreement often about new
> cases... and we do this on the basis of a very limited
> environmental context available to us. The child or the adult
> doesn't have much information that enables the mature person to
> construct a moral system that will in fact apply to a rich range of
> cases, and yet that happens....whenever we see a very rich,
> intricate system developing in a more or less uniform way on the basis
> of rather restricted stimulus conditions, we have to assume that there
> is a very powerful, very rich, highly structured innate component that
> is operating in such a way as to create that highly specific system on
> the basis of the limited data available to it. (Chomsky, quoted in
> Mikhail 2005).
> 



Here Chomsky points to four similarities between the development of
linguistic knowledge and the development of moral knowledge:



> 
> 
> L1: A child raised in a particular linguistic community almost
> inevitably ends up speaking an idiolect of the local language despite
> lack of sufficient explicit instruction, lack of extensive negative
> feedback for mistakes, and grammatical mistakes by caretakers.
> 
> 
> 
> M1: A child raised in a particular moral community almost inevitably
> ends up judging in accordance with an idiolect of the local moral code
> despite lack of sufficient explicit instruction, lack of sufficient
> negative feedback for moral mistakes, and moral mistakes by
> caretakers.
> 
> 
> 
> L2: While there is great diversity among natural languages, there are
> systematic constraints on possible natural languages.
> 
> 
> 
> M2: While there is great diversity among natural moralities, there are
> systematic constraints on possible natural moralities.
> 
> 
> 
> L3: Language-speakers obey many esoteric rules that they themselves
> typically cannot articulate or explain, and which some would not even
> recognize.
> 
> 
> 
> M3: Moral agents judge according to esoteric rules (such as the
> doctrine of double effect) that they themselves typically cannot
> articulate or explain, and which some would not even recognize.
> 
> 
> 
> L4: Drawing on a limited vocabulary, a speaker can both produce and
> comprehend a potential infinity of linguistic expressions.
> 
> 
> 
> M4: Drawing on a limited moral vocabulary, an agent can produce and
> evaluate a very large (though perhaps not infinite) class of
> action-plans, which are ripe for moral judgment.
> 
> 
> 



We will now explain and evaluate each of these pairs of claims in
turn.



L1/M1 refer to Chomsky's *poverty of the stimulus*
argument: despite receiving little explicit linguistic and grammatical
instruction, children develop language rapidly and at a young age, and
quickly come to display competence applying complex grammatical rules.
Similarly, Mikhail and other proponents of the analogy argue that
children acquire moral knowledge at a young age based on relatively
little explicit instruction. However, critics of the analogy point out
several points of difference. First, children actually receive quite a
bit of explicit moral instruction and correction, and in contrast with
the linguistic case, this often takes the form of explicit statements
of moral rules: 'don't hit,' 'share,'
and so on. Secondly, there is debate over the age at which children
actually display moral competence. Paul Bloom (2013; see also Blake,
McAuliffe, and Warneken 2014) has argued that babies display moral
tendencies as early as 3-6 months, but others (most famously
Kohlberg (1969) and Piaget (1970)) have argued that children are not
fully competent with moral judgment until as late as 8-12 years,
by which time they have received quite a bit of moral instruction,
both implicit and explicit. A related point concerns the ability to
receive instructions: in the case of language, a child requires some
linguistic knowledge or understanding in order even to receive
instruction: a child who has no understanding of language will not
understand instructions given to her. But in the moral case, a child
need not understand moral rules in order to be instructed in them, so
there is less need to posit some innate knowledge or understanding.
Nichols et al. (2016) have conducted a series of experiments using
statistical learning and Bayesian modeling to show how children might
learn complex rules with scant input (see also Nichols 2021). Finally,
while children may initially acquire the moral values present in their
environment, they sometimes change their values or develop their own
values later in life in ways that present spontaneously and with
little conscious effort. This is in marked contrast with language; as
any second-language learner will recognize, acquiring a new language
later in life is effortful and, even if one succeeds in achieving
fluency, the first language is rarely lost. Lastly, as Prinz (2008)
points out, children are punished for moral violations, which may
explain why they are quicker to learn moral than grammatical
rules.



L2/M2 refer to the existence of so-called *linguistic
universals*: structures present in all known languages. Whether
this is true in the moral case is controversial, for reasons
we'll discuss further below. Prinz (2008) and Sripada (2004)
have argued that there are no *exceptionless* moral universals,
unless one phrases or describes the norms in question in such a way as
to render them vacuous. Sripada uses the example 'murder is
wrong' as a vacuous rule: while this might seem like a plausible
candidate for a moral universal, when we consider that
'murder' refers to a wrongful act of killing, we can see
that the norm is not informative. But Mikhail might respond by
claiming that the fact that all cultures recognize a subset of
intentional killings as morally wrong, even if they differ in how they
circumscribe this subset, is itself significant, and the relevant
analogy here would be with the existence of categories like
'subject', 'verb', and 'object' in
all languages, or with features like recursion, which are present in
the grammars of all natural languages (but see Everett 2005).



L3/M3 refer to the patterns displayed by grammatical and moral
intuitions. In the case of language, native speakers can recognize
grammatical and ungrammatical constructions relatively easily, but
typically cannot articulate the rules underlying these intuitions. In
the case of moral grammar, the analogy claims, the same is true: we
produce moral intuitions effortlessly without being able to explain
the rules underlying them. Indeed, in both cases, the rules underlying
the judgments might be quite esoteric and difficult for native
speakers to learn and understand.



L4/M4 refer to the fact that we can embed linguistic phrases within
other linguistic phrases to create novel and increasingly complex
phrases and sentences. This property is known as *recursion*,
and is present in all known natural languages (indeed, Chomsky
suggests that perhaps recursion is the only linguistic universal; see
Hauser, Chomsky & Fitch 2002; but see Everett 2005). For
instance, just as phrases can be embedded in other phrases to form
more complex phrases:



> 
> the calico cat \(\rightarrow\) the calico cat (that the dog chased)
> \(\rightarrow\) the calico cat (that the dog [that the breeding
> conglomerate wanted] chased) \(\rightarrow\) the calico cat (that the
> dog [that the breeding conglomerate{that was bankrupt} wanted] chased)
> 



so the descriptions of actions that are morally assessed can be
embedded in other action descriptions to produce novel action
descriptions (Harman 2008, 346). For example:



> 
> It's wrong to \(x \rightarrow\) It's wrong to coerce
> someone to \(x \rightarrow\) It's wrong to persuade someone to
> coerce someone to \(x\).
> 



The point is twofold: first, we can create complex action
descriptions; second, we can evaluate novel and complex actions and
respond with relatively automatic intuitions of grammatical or moral
permissibility.



Mikhail (2011: 43-48) uses experimental evidence of judgments
about trolley problems to argue that our moral judgments are generated
by imposing a deontic structure on our representation of the causal
and evaluative features of the action under consideration. Mikhail
points to a variation on the poverty of the stimulus argument, which
he calls the *poverty of the perceptual stimulus* (Mikhail
2009: 37): when faced with a particular moral situation, we draw
complex inferences about both act and actor based on relatively little
data. Mikhail (2010) uses this argument against models of moral
judgment as affect-driven intuitions:



> 
> Although each of these rapid, intuitive, and highly automatic moral
> judgments is occasioned by an identifiable stimulus, how the brain
> goes about interpreting these complex action descriptions and
> assigning a deontic status to each of them is not something revealed
> in any obvious way by the surface structure of the stimulus itself.
> Instead, an intervening step must be postulated: an intuitive
> appraisal of some sort that is imposed on the stimulus prior to any
> deontic response to it. Hence, a simple perceptual model, such as the
> one implicit in Haidt's (2001) influential model of moral
> judgment, appears inadequate for explaining these intuitions, a point
> that can be illustrated by calling attention to the unanalyzed link
> between eliciting situation and intuitive response in Haidt's
> model
> 



Unlike the traditional poverty of the stimulus argument, this version
does not rely on developmental evidence, but on our ability to quickly
and effortlessly appraise complicated scenarios, such as variations on
trolley problems, in a way that is independent of their superficial
features (e.g., the way they are described), and then issue
normative judgments. The postulated intervening step is like the
unconscious appeal to rules of grammar, and the evidence for such a
step must come from experiments showing that we do, in fact, have such
intuitions, and that they conform to predictable patterns.



The linguistic analogy relies on experimental evidence about the
nature and pattern of our moral intuitions, and it outlines an
important role for experiments in moral theory. If the analogy holds,
then a descriptively adequate moral theory must be based on the
judgments of competent moral judges (although a reformist moral theory
need not, or at least not to the same extent), just as grammatical
rules are constructed based on the judgments of competent speakers. A
pressing task will be the systematic collection of such judgments. The
analogy also suggests a kind of rationalism about moral judgment,
since it posits that our judgments result from the unconscious
application of rules to cases. Finally, the analogy might have
metaethical implications. Just as we can only evaluate grammaticality
of utterances relative to a language, it may be that we can only
evaluate the morality of an action relative to a specific moral
system. How to individuate moralities, and how many (assuming there
are multiple ones) there are, is a question for further empirical
investigation, and here again experimental evidence will play a
crucial role.


### 2.5 Cross-Cultural Experimental Moral Philosophy



Guided by the idea that variation in some judgments might
challenge our trust in them (Machery 2017, Chapter 4), the
negative program has led experimental philosophers to examine whether
moral judgments vary across cultures and other demographic groups (see
also Graham et al. 2016; Doris et al. 2020). Early research
focused on the distinction between causing harm as a means or as a
side effect, and failed to find any cultural variation using the
footbridge and the bystander versions of the trolley case (Hauser
et al. 2007; Moore et al. 2011), but a few articles have
observed differences among Americans, Russians and Chinese (Ahlenius
& Tannsjo 2012), English and Chinese (Gold et
al. 2014), and Yali horticulturalists in Papua (Sorokowski
et al. 2020). A recent study of moral judgments in 45 countries found
that people find it less acceptable to cause someone's death as a
means to prevent a greater harm than as a mere side effect; they
also find it less acceptable to cause someone's death as a means to
prevent a greater harm when the death results from "personal
force", i.e., when the force that impacts the victim originates
in the agent's muscles; but the interaction between these two factors,
which had been observed in the USA, was only found in
Western countries (Bago et al. 2022). Moral dilemmas that
investigate the permissibility of causing harm to prevent a greater
harm also elicit different judgments from men and women: in a
metaanalysis of 40 studies, men were more likely to find it
permissible to cause harm to prevent a greater harm in this kind
of moral dilemmas (Friesdorf et al. 2015). Hannikainen, Machery and
Cushman (2018) have also shown that Millenials are more likely to find
it permissible to cause harm to prevent a greater harm in the
footbridge case than Gen Xers and Boomers, suggesting that the
relevant moral norms might have culturally evolved. 



Variation is not limited to sacrificial dilemmas (Stich and Machery in
press). Cultural factors moderate the influence of valence on judgment
about the intentionality of action that was discussed above (Robbins,
Shepard and Rochat 2017): in two rural, traditional cultures
(Samoa and Vanuatu) people were more likely to judge the good
side effect than the bad side effect as intentional if the protagonist
had a high status. 



Another area of investigation focuses on the distinction between norms
that are thought to be moral and norms that aren't (see also Machery
and Stich 2022 for the cross-cultural work on the
moral/conventional distinction). Buchtel et al. (2015) have shown that
the Mandarin translation of "immoral" applies to a
surprisingly different set of behaviors than "immoral" in
English: the former primarily applies to behaviors viewed as
uncivilized, the latter often to harmful behavior (see also
Dranseika, Berniunas & Silius 2018).
Berniunas (2020) extends this research to the Mongolian
translation of "moral." Asking people to classify norms as
moral and non-moral, Levine and colleagues (2021) have also shown that
religious affiliation influences what counts as moral: religious Jews
and non-believers have a very narrow moral domain, while Christians
and Muslims tend to have a broad moral domain; surprisingly, Hindus
fail to distinguish moral from non-moral norms (see
also Dranseika, Berniunas & Sousa 2016). This kind
of findings has led Machery (2018) to propose that morality is a
cultural invention that is not found in every culture (see also Stich
2018).



Judgments related to free will, control, blame, and punishment also
vary across cultures (Hannikainen et al. 2019; for a different line of
cross-cultural research on free will, see Sarkissian et al.
2010). In most cultures, people deny free will and control (and
thus blame and punish less) when the agent's action is described
as antecedently caused; by contrast, they assign free will and
control when the action originates stems from the agent's own
will even if she could not have done otherwise (a situation
illustrated by Frankfurt cases). East Asians, however, differ in
treating these two kinds of situations similarly: if the surrounding
circumstances undercut the agent's capacity to have done
otherwise, they tend to deny her free will and control. East Asians'
greater attention to contextual factors when explaining behavior
(Choi, Nisbett and Norenzayan 1999) might account for this finding
(for related research, see Buchtel et al. 2018). Berniunas and
colleagues (2021) have even argued that the concept of free will is a
culture-specific concept, not found in most cultures. 


## 3. Character, Wellbeing, Emotion, and Moral Standing



Until the 1950s, modern moral philosophy had largely focused on either
consequentialism or deontology. The revitalization of virtue ethics
led to a renewed interest in virtues and vices (e.g., honesty,
generosity, fairness, dishonesty, stinginess, unfairness), in
*eudaimonia* (often translated as 'happiness' or
'flourishing'), and in the emotions. In recent decades,
experimental work in psychology, sociology, and neuroscience has been
brought to bear on the empirical grounding of philosophical views in
these areas.


### 3.1 Character and Virtue



A virtue is a complex disposition comprising sub-dispositions to
notice, construe, think, desire, and act in characteristic ways. To be
generous, for instance, is (among other things) to be disposed to
notice occasions for giving, to construe ambiguous social cues
charitably, to desire to give people things they want, need, or would
appreciate, to deliberate well about what they want, need, or would
appreciate, and to act on the basis of such deliberation.
Manifestations of such a disposition are observable and hence ripe for
empirical investigation. Virtue ethicists of the last several decades
have sometimes been optimistic about the distribution of virtue in the
population. Alasdair MacIntyre claims, for example, that
"without allusion to the place that justice and injustice,
courage and cowardice play in human life very little will be genuinely
explicable" (1984: 199). Julia Annas
(2011: 8-10) claims that "by the time we reflect
about virtues, we already have some." Linda Zagzebski (2010)
provides an "exemplarist" semantics for virtue terms that
only gets off the ground if there are in fact many virtuous
people.



Starting with Owen Flanagan's *Varieties of Moral
Personality* (1993), philosophers began to worry that empirical
results from social psychology were inconsistent with the structure of
human agency presupposed by virtue theory. In this framework, people
are conceived as having more or less fixed traits of character that
systematically order their perception, cognition, emotion, reasoning,
decision-making, and behavior. For example, a generous person is
inclined to notice and seek out opportunities to give supererogatorily
to others. The generous person is also inclined to think about what
would (and wouldn't) be appreciated by potential recipients, to
feel the urge to give and the glow of satisfaction after giving, to
deliberate effectively about when, where, and how to give to whom, to
come to firm decisions based on such deliberation, and to follow
through on those decisions once they've been made. Other traits
are meant to fit the same pattern, structuring perception, cognition,
motivation, and action of their bearers. Famous results in social
psychology, such as Darley and Batson's (1973) Good Samaritan
experiment, seem to tell against this view of human moral conduct.
When someone helps another in need, they may do so simply because they
are not in a rush, rather than because they are expressing a fixed
trait like generosity or compassion.



In the virtue-theoretic framework, people are not necessarily assumed
to already be virtuous. However, they are assumed to be at least
potentially responsive to the considerations that a virtuous person
would ordinarily notice and take into account. Flanagan (1993),
followed by Doris (1998, 2002, in press), Harman (1999, 2000), and
Alfano (2013), made trouble for this framework by pointing to social
psychological evidence suggesting that much of people's
thinking, feeling, and acting is instead predicted by (and hence
responsive to) situational factors that don't seem to count as
reasons at all--not even bad reasons or temptations to vice.
Early discussions of these situational factors
emphasized influences such as ambient sensibilia (sounds, smells,
light levels, etc.), seemingly trivial and normatively irrelevant
inducers of positive and negative moods, order of presentation of
stimuli, and a variety of framing and priming effects, many of which
are reviewed in Alfano (2013:
 40-50).[7] 
 It's
 worth emphasizing the depth of the problem these studies appeared
to pose. It's not that they suggest that most people
aren't virtuous (although they do suggest that as well).
It's that they suggest that they undermine the entire framework
in which people are conceived as cognitively sensitive and
motivationally responsive to reasons. Someone whose failure to act
virtuously because they gave in to temptation can be understood in the
virtue-theoretic framework. Someone whose failure to act virtuously
because they'd just been subliminally primed with physical
coldness, which in turn is metaphorically associated with social
coldness, finds no place in the virtue-theoretic framework. These
sorts of effects push us to revamp our whole notion of agency and
personhood (Doris 2015).



Some of the most surprising findings touted by critics of virtue
ethics (e.g., social priming) now appear to be
unreplicable (for discussion, see Alfano 2018), but this outcome
does not provide much solace to virtue theorists. Early estimates
suggested that individual difference variables typically explain less
than 10% of the variance in people's behavior (Mischel
1968)--though, as Funder and Ozer (1983) pointed out, situational
factors may explain less than
 16%.[8]
 More recent aggregated evidence indicates that situational factors
explain approximately twice as much of the variance in human behavior
as the five main trait factors (Rauthmann et al. 2014). Convergent
evidence from both lexicographical and survey studies indicates that
there are at least five dimensions of situations that reliably predict
thought, feeling, and behavior: (1) negative valence, (2) adversity,
(3) duty, (4) complexity, and (5) positive valence (Rauthmann and
Sherman 2018).



According to Doris (2002, in press), the best explanation of this lack
of cross-situational consistency is that the great majority of people
have local rather than global, traits: they are not honest,
courageous, or greedy, but they may be honest-while-in-a-good-mood,
courageous-while-sailing-in-rough-weather-with-friends, and
greedy-unless-watched-by-fellow-parishioners. In contrast, Christian
Miller (2013, 2014) thinks the evidence is best explained by a theory
of mixed global traits, such as the disposition to (among other
things) help because it improves one's mood. Such traits are
global, in the sense that they explain and predict behavior across
situations (someone with such a disposition will, other things being
equal, typically help so long as it will maintain her mood), but
normatively mixed, in the sense that they are neither virtues nor
vices. Mark Alfano (2013) goes in a third direction, arguing that
virtue and vice attributions tend to function as self-fulfilling
prophecies. People tend to act in accordance with the traits that are
attributed to them, whether the traits are minor virtues such as
tidiness (Miller, Brickman, & Bolen 1975) and ecology-mindedness
(Cornelissen et al. 2006, 2007), major virtues such as charity (Jensen
& Moore 1977), cooperativeness (Grusec et al. 1978), and
generosity (Grusec & Redler 1980), or vices such as cutthroat
competitiveness (Grusec et al. 1978). On Alfano's view,
when people act in accordance with a virtue, they often do so not
because they possess the trait in question, but because they think
they do or because they know that other people think they do. He calls
such simulations of moral character *factitious virtues*, and
even suggests that the notion of a virtue should be revised to include
reflexive and social
 expectations.[9]



It might seem that the criticisms that motivate these novel approaches
to virtue miss their mark. After all, virtue ethicists needn't
(and often don't) commit themselves to the claim that almost
everyone *is* virtuous. Instead, many argue that virtue is the
normative goal of moral development, and that people mostly fail in
various ways to reach that goal. The argument from the fact that most
people's dispositions are not virtues to a rejection of orthodox
virtue ethics, then, might be thought a *non sequitur*, at
least for such views. But empirically-minded critics of virtue ethics
do not stop there. They all have positive views about what sorts of
dispositions people have *instead* of virtues. These
dispositions are alleged to be so structurally dissimilar from virtues
(as traditionally understood) that it may be psychologically
unrealistic to treat (traditional) virtue as a regulative ideal. What
matters, then, is the width of the gap between the descriptive and the
normative, between the (structure of the) dispositions most people
have and the (structure of the) dispositions that count as
virtues.



Three leading defenses against this criticism have been offered. Some
virtue ethicists (Kupperman 2009) have conceded that virtue is
extremely rare, but argued that it may still be a useful regulative
ideal. Others (Hurka 2006; Merritt 2000) have attempted to weaken
the concept of virtue in such a way as to enable more people, or at
least more behaviors, to count as virtuous. Still others (Kamtekar
2004; Russell 2009; Snow 2010; Sreenivasan 2002) have
challenged the situationist evidence or its interpretation. While it
remains unclear whether these defenses succeed, grappling with the
situationist challenge has led both defenders and challengers of
virtue ethics to develop more nuanced and empirically informed
 views.[10]


### 3.2 Wellbeing, Happiness, and the Good Life



Philosophers have always been interested in what makes a human life go
well, but recent decades have seen a dramatic increase in both
psychological and philosophical research into happiness, well-being,
and what makes for a good life. It is important to distinguish here
between 'good life' in the sense of a life that goes well
for the one who lives it, and a *morally* good life, since
philosophers have long debated whether a morally bad person could
enjoy a good life. The empirical study of wellbeing focuses primarily
on lives that are good in the former sense: good for the person whose
life it is. Second, we need to distinguish between a hedonically good
life and an overall good life. A life that is hedonically good is one
that the subject experiences as pleasant; an overall good life might
not contain much pleasure but might be good for other reasons, such as
what it accomplishes. We might decide, after investigation, that an
overall good life must be a hedonically good life, but the two
concepts are distinct.



With these distinctions in mind, we can see the relevance of
experimental evidence to investigations in this area. First and
perhaps most obviously, experiments can investigate our intuitions
about what constitutes a good life, thereby giving us insight into the
ordinary concepts of happiness, well-being, and flourishing. To this
end, Phillips, Nyholm, and Liao (2014) investigated intuitions about
the relationship between morality and happiness. Their results suggest
that the ordinary conception of happiness involves both descriptive
and normative components: specifically, we judge that people are happy
if they are experiencing positive feelings that they ought to
experience. So, to use their examples, a Nazi doctor who gets positive
feelings from conducting his experiments is not happy. By contrast, a
nurse who gets positive feelings from helping sick children is happy,
though a nurse who is made miserable by the same actions is not
happy.



Another set of experimental findings bearing on this question involves
Nozick's (1974: 44-45) experience machine thought
experiment. In response to the hedonist's claim that pleasure is
the only intrinsic good, Nozick asks us to consider the following:



> 
> Suppose there was an experience machine that would give you any
> experience you desired. Super-duper neuropsychologists could stimulate
> your brain so that you would think and feel you were writing a great
> novel, or making a friend, or reading an interesting book. All the
> time you would be floating in a tank, with electrodes attached to your
> brain. Should you plug into this machine for life, preprogramming your
> life experiences? [...] Of course, while in the tank you
> won't know that you're there; you'll think that
> it's all actually happening [...] Would you plug in?
> 



Nozick argues that our response to the experience machine reveals that
well-being is not purely subjective: "We learn that something
matters to us in addition to experience by imagining an experience
machine and then realizing that we would not use it." De Brigard
(2010) reports finding that subjects' intuitions about the
experience were different if they were told they were already in such
a machine, in which case they would not choose to unplug; he explains
this in terms of the status quo bias. Weijers (2014) goes further,
asking subjects about Nozick's original scenario while also
asking them to justify their response; he found that many of the
justifications implied a kind of imaginative resistance to the
scenario or cited irrelevant factors. He also found that respondents
were more likely to say that a 'plugged in life' would be
better when they were choosing for someone else, rather than for
themselves. Lohr (2019) shows that a third of philosophers would
stay in the machine and recommend it to others. Hindriks and Douven
(2018) further show that people are more likely to agree to choose
pleasurable, but illusory experiences in scenarios that are more
realistic than the experience machine. 



A second type of study involves investigating the causes and
correlates of happiness, well-being, and life-satisfaction. These
experiments look at the conditions under which people report positive
affect or life-satisfaction, as well as the conditions under which
they judge that their lives are going well. This is distinct from the
first type of research, since the fact that someone reports an
experience as being pleasurable does not necessarily tell us whether
they would judge that experience to be pleasurable for someone else;
there may be asymmetries in first- and third-person evaluations.
Furthermore, this type of research can tell us how various candidates
contribute to well-being from a first-person perspective, but that
doesn't settle the question of the concept of a good life. I
might judge that my life is going well, yet fail to notice that I am
doing so because I am in a very good mood, and that in fact I am not
accomplishing any of my goals; if confronted with another person in a
similar situation, I might not make the same judgment. Which of these
judgments best represents our concept of well-being is a tricky
question, and a normative one since experimental evidence alone may
not settle it. As it turns out, experiments have uncovered a number of
factors that influence our own reports and assessments of pleasure and
well-being. We will discuss two areas of research in particular:
reports of pleasures and pains, and judgments of life
satisfaction.



First, in the realm of hedonic evaluation, there are marked
divergences between the aggregate sums of in-the-moment pleasures and
pains and ex post memories of pleasures and pains. For example, the
remembered level of pain of a colonoscopy is well-predicted by the
average of the worst momentary level of pain and the final level of
pain; furthermore, the duration of the procedure has no measurable
effect on ex post pain ratings (Redelmeier & Kahneman 1996). What
this means is that people's after-the-fact summaries of their
hedonic experiences are not simple integrals with respect to time of
momentary hedonic tone. If the colonoscopy were functionally completed
after minute 5, but arbitrarily prolonged for another 5 minutes so
that the final level of pain was less at the end of minute 10 than at
the end of minute 5, the patient would retrospectively evaluate the
experience as less painful. This complicates accounts of well-being in
terms of pleasure (for example, Bentham's 1789/1961 hedonism)
insofar as it raises the question whether the pleasure being measured
is pleasure as experienced in the moment, or retrospectively: if, in
the very act of aggregating pleasure, we change the way we evaluate
it, this is a complication for hedonism and for some versions of
utilitarianism. Since well-being is supposed to be a normative notion
capable of guiding both individual actions and social policy, findings
like these also call into question what, exactly, we ought to be
seeking to maximize: pleasurable moments, or the overall retrospective
evaluation of pleasure.



Such findings have led some philosophers to seek out alternatives to
hedonism in hopes of establishing a more empirically stable
underpinning for well-being: in particular, the idea that well-being
consists in life satisfaction. The most prominent psychologist in this
field is Ed
 Diener[11]
 whose Satisfaction with Life Scale asks participants to agree or
disagree with statements such as, "I am satisfied with my
life" and "If I could live my life over, I would change
almost nothing." These questions seem to get at more stable and
significant features of life than hedonic assessments in terms of
pleasure and pain, and one might expect the responses to be more
consistent and robust. However, two problems arise. The first is that
participants' responses to life satisfaction questionnaires may
not be accurate reports of standing attitudes. Fox and Kahneman
(1992), for instance, showed that, especially in personal domains
people seem to value (friends and love life), what predicts
participants' responses is not recent intrapersonal factors but
social comparison. Someone who has just lost a friend but still thinks
of herself as having more friends than her peers will tend to report
higher life satisfaction than someone who has just gained a friend but
who still thinks of himself as having fewer friends than his
peers.



Life satisfaction surveys were also believed to be subject to
order effects. If a participant is asked a global life satisfaction
question and then asked about his romantic life, the correlation
between these questions tends to be near zero, but if the participant
is asked the dating question first, the correlation tends to be high
and positive (Strack, Martin & Schwarz
1988). Relatedly, weather and life-satisfaction were
correlated when subjects were asked about weather first, but not when
the weather question followed the life-satisfaction query (Schwarz
& Clore 1983). Recent work has however cast doubts on this
kind of results: Schimmack and Oishi (2005) did not
replicate Strack et al.'s (1988) findings and Lucas and Lawless
(2013) found no evidence for an effect of weather on
life-satisfaction judgments (but see Connolly
 2013).[12]
 Recent surveys suggest that the instability of life satisfaction
surveys, which some philosophers have been taken for granted, has been
exaggerated (Lucas 2018). 



Schwarz's findings and similar ones have led some philosophers (e.g.,
Haybron 2008) to argue that life-satisfaction judgments are too
arbitrary to ever satisfy the requirements of a theory of well-being.
In response, Tiberius and Plakias (2011) argue for an idealized
life-satisfaction theory they call *value-based life
satisfaction*, suggesting that by asking subjects to consider
their life-satisfaction while attending to the domains they most value
much of the instability plaguing the studies described above is
removed, a claim they support with research showing that judgments
made after priming subjects to think about their values demonstrate
higher levels of retest stability (Schimmack & Oishi 2005).


### 3.3 Emotion and Affect



As much of the previous discussion reveals, the relationship between
emotion and moral judgment is one of the central concerns of both
traditional and experimental moral philosophy. Our discussion of this
topic will focus on two types of research: the role of emotion in
moral reasoning generally, and the role of a specific
emotion--disgust--in moral judgments.



One debate concerns whether hot, emotion-driven reasoning is
necessarily better or worse than reasoning based only on cooler, more
reflective thinking--a distinction sometimes referred to using
Kahneman's terminology of system 1/system 2 thinking. The
terminology is not perfect, though, because Kahneman's terms map
onto a quick, automatic, unconscious system of judgments (system 1)
and a slow, effortful, deliberative decision-making process (system
2), and as we saw above, this is not a distinction between emotion and
reason, since rule-based judgments can be automatic and unconscious
while emotional judgments might be effortful and conscious. The debate
between Mikhail and Haidt is a debate over the extent to which
emotions rather than rules explain our moral judgments; Singer and
Greene's arguments against deontology rest on the claim that
emotion-backed judgments are less justified than their utilitarian
counterparts.



One reason for thinking that moral judgments essentially involve some
emotional component is that they tend to motivate us.
*Internalism* is the view that there is a necessary connection
between moral judgment and motivation. This contrasts with
*externalism*, which doesn't deny that moral judgments
are usually motivating, but does deny that they are necessarily so, as
the link between judgment and motivation is only contingent. Since
emotions are intrinsically motivational, showing that moral judgments
consist, even in part, of emotions would vindicate internalism. One
route to this conclusion has involved surveying people's
intuitions about moral judgment. Nichols (2002: 289) asked subjects
whether an agent who "had no emotional reaction to hurting other
people" but claims to know that hurting others is wrong really
understands that hurting others is wrong. He found that most subjects
did attribute knowledge in such cases, suggesting that the ordinary
concept of moral judgment is externalist, a claim that is further
supported by Strandberg and Bjorklund (2013). An additional
source of evidence comes from psychopaths and patients with traumatic
brain injuries, both of whom show evidence of impaired moral
functioning--though how one regards this evidence depends on
which perspective one begins with: while externalists (Nichols
2002; Roskies 2003) claim that the existence of psychopaths
provides a counterexample to the claim that moral judgment is
motivating (since psychopaths lack empathy and an aversion to harming
others), internalists (Smith 1994; Maibom 2005; Kennett
& Fine 2008) argue that psychopaths don't actually make
full-fledged moral judgments. Psychologist Robert Hare (1993: 129)
quotes a researcher as saying that, they "know the words but not
the music." Psychopaths also display other cognitive and
affective deficiencies, as evidenced by their poor decision-making
skills in other areas. This may mean that they should not be taken as
evidence against internalism.



A reason for thinking that moral judgments ought not involve emotion
is that emotions sometimes seem to lead to judgments that are
distorted or off-track, or that seem otherwise unjustified. One
emotion in particular is often mentioned in this context: disgust.
This emotion, which seems to be unique to human animals and emerges
relatively late in development (from the ages of about 5-8),
involves a characteristic gaping facial expression, a tendency to
withdraw from the object of disgust, a slight reduction in body
temperature and heart rate, and a sense of nausea and the need to
cleanse oneself. In addition, the disgusted subject is typically
motivated to avoid and even expunge the offending object, experiences
it as contaminating and repugnant, becomes more attuned to other
disgusting objects in the immediate environment, and is inclined to
treat anything that the object comes in contact with (whether
physically or symbolically) as also disgusting. This last
characteristic is often referred to as 'contamination
potency' and it is one of the features that makes disgust so
potent and, according to its critics, so problematic. The disgust
reaction can be difficult to repress, is easily recognized, and
empathically induces disgust in those who do recognize
 it.[13]
 There are certain objects that almost all normal adults are disgusted
by (feces, decaying corpses, rotting food, spiders, maggots, gross
physical deformities). But there is also considerable intercultural
and interpersonal variation beyond these core objects of disgust,
where the emotion extends into food choices, sexual behaviors,
out-group members, and violations of social norms. Many studies have
claimed to show that disgust is implicated in harsher moral judgments
(Schnall, Haidt, & Clore 2008), citing experiments in which
subjects filling out questionnaires in smelly or dirty rooms evaluated
moral transgressions more harshly. Many of these studies have however
failed to replicate, raising doubts about the influence of incidental
disgust on moral judgment (e.g., Johnson, Cheung &
Donnellan's (2014) failed replication of Schnall et al. (2008);
Ghelfi et al. 2020). 



Others have gone further and argued that disgust might itself cause or
comprise a part of moral judgment (Haidt 2001; Wheatley & Haidt
2005). If this is true, critics argue, we ought to be wary of those
judgments, because disgust has a checkered past in multiple senses.
First, it's historically (and currently) associated with racism,
sexism, homophobia and xenophobia; the language of disgust is often
used in campaigns of discrimination and even genocide. Secondly,
disgust's evolutionary history gives us reason to doubt it.
Kelly (2011) argues that the universal bodily manifestations of
disgust evolved to help humans avoid ingesting toxins and other
harmful substances, while the more cognitive or symbolic sense of
offensiveness and contamination associated with disgust evolved to
help humans avoid diseases and parasites. This system is later
recruited for an entirely distinct purpose: to help mark the
boundaries between in-group and out-group, and thus to motivate
cooperation with in-group members, punishment of in-group defectors,
and exclusion of out-group members.



If Kelly's account of disgust is on the right track, it seems to
have a number of important moral upshots. One consequence, he argues,
is "disgust skepticism" (139), according to which the
combination of disgust's hair trigger and its ballistic
trajectory mean that it is especially prone to incorrigible false
positives that involve unwarranted feelings of contamination and even
dehumanization. Hence, "the fact that something is disgusting is
not even remotely a reliable indicator of moral foul play" but
is instead "irrelevant to moral justification" (148).



It is important to note that the skeptical considerations Kelly raises
are specific to disgust and its particular evolutionary history, so
they aren't intended to undermine the role of all emotions in
moral judgment. Still, if Kelly is correct, and if disgust is
implicated in lots of moral judgments, we may have a reason to be
skeptical of many of our judgments. Plakias (2011, 2017) argues
against the first half of this antecedent, claiming that Kelly and
other 'disgust skeptics' are wrong to claim that the
purposes of moral and physical disgust are totally distinct; she
suggests that disgust is sometimes a fitting response to moral
violations that protects against social contagion. May (2014) argues
against the second half, claiming that disgust's role in moral
judgment has been significantly overblown; at most, we have evidence
that disgust can, in certain cases, slightly amplify moral judgments
that are already in place. Recent empirical work indicates that
incidental disgust has little effect on the harshness of moral
judgments, though dispositional disgust-sensitivity does (Landy &
Goodwin 2015; Landy & Piazza 2019).


### 3.4 Moral Standing



A creature has moral standing if its interests are morally relevant to
the agents whose actions impact it. Stones don't have moral
standing, people do. Moral philosophers disagree about the grounds of
moral standing, i.e., that in virtue of which a creature has moral
standing. Some argue that the capacity to feel gives a creature moral
standing (e.g., Bentham 1781/2011), others favor autonomy (e.g., Kant
2001). What about lay people (for review, see Goodwin 2015)? According
to Gray, Gray, and Wegner (2007), lay people side with Bentham:
Whether a creature can suffer determines whether it has morally
relevant interests (see also Robbins & Jack 2006 and Knobe &
Prinz 2008). 



However, the influence of another historical tradition, which like
Kant highlights the connection between rationality and autonomy and
moral standing, suggests that the capacity to feel might not be the
whole story. Sytsma and Machery (2012) provided evidence for the
two-source hypothesis: both rationality and the capacity to feel
underwrite the ascription of moral standing by lay people. Others have
since identified further factors that influence the ascription of
moral standing (e.g., Piazza, Landy & Goodwin 2014), and they have
examined how information about the grounds of moral standing can be
used by people in a self-serving manner (Piazza & Loughnan 2016).
Recent work connects moral standing ascription to, on the one hand,
vegetarianism and the treatment of animals (e.g., Piazza &
Loughnan 2016) and, on the other, the psychological processes
underlying dehumanization (Machery 2021).


## 4. Metaethics and Experimental Moral Philosophy



Metaethics steps back from moral theorizing to ask about the nature
and function of morality. While first-order ethics seeks to explain
what we should do, metaethics seeks to explain the status of those
theories themselves: what are their metaphysical commitments, and what
evidence do we have for or against them? Which epistemology best
characterizes our moral practices? What is the correct semantics for
moral language? These questions might not seem obviously empirical,
but insofar as it attempts to give an account of moral semantics,
epistemology, and ontology, metaethics aims, in part, to capture or
explain what we do when we engage in moral talk, judgment, and
evaluation. To the extent that metaethics sees itself as
characterizing our ordinary practice of morality, it is therefore
answerable to empirical data about that practice. To the extent that a
theory claims that we are mistaken or in widespread error about the
meaning of moral language, or that we lack justification for our core
moral beliefs, this is taken to be a strike against that theory. For
example, relativism is often criticized on the grounds that it
requires us to give up the (putatively) widespread belief that moral
claims concern objective matters of fact and are true or false
independently of our beliefs or attitudes. We have already seen
several ways that experimental data bears on theories about moral
reasons (the debate between internalists and externalists) and the
epistemology of moral judgment (the debate over the role of
intuitions). In this section we will examine experimental
contributions to the debate over moral realism, arguments about moral
disagreement, and moral language.


### 4.1 Folk Metaethics and Moral Realism



Much contemporary metaethics relies on assumptions about the nature of
ordinary moral thought, discourse, and practice; metaethicists tend to
see their project as essentially conservative. For example, Michael
Smith writes that the first step in metaethical theorizing is to
"identify features that are manifest in ordinary moral
practice" and the second step is to "make sense of a
practice having these features." (1994) This assumption has had
a major impact on the debate between realists and anti-realists, with
realists claiming to best capture the nature of ordinary moral
discourse: "We begin as (tacit) cognitivists and realists about
ethics," says Brink (1989), and then "we are led to some
form of antirealism (if we are) only because we come to regard the
moral realist's commitments as untenable... Moral realism
should be our metaethical starting point, and we should give it up
only if it does involve unacceptable metaphysical and epistemological
commitments."



But experimental work has cast doubt on this claim, beginning with
Darley and Goodwin (2008), and continued by James Beebe (2014) and
others (Wright et al. 2013; Campbell & Kumar 2012; Goodwin &
Darley 2010; Sarkissian et al. 2011; but see Sousa et al.
2021; for review, see Polzler & Wright 2019). Goodwin
and Darley asked subjects to rate their agreement with statements
drawn from the moral, ethical, and aesthetic domain, and asked
subjects whether they agreed with the statement (for example,
"before the 3rd month of pregnancy, abortion for any reason (of
the mother's) is morally permissible,"), whether they
thought it represented a *fact* or an *opinion or
attitude*, and whether, if someone were to disagree with them
about the statement, at least one of the disputants would have to be
mistaken. (We will say more about the authors' use of
disagreement as a proxy for realism in the following section.) In
general, subjects rated moral statements as less factual than
obviously factual statements (e.g. "the earth is at the center
of the universe,") but more factual than statements about
matters of taste or etiquette. What is striking about these findings
is not just that people are not straightforwardly realist, but that
they seem to treat moral questions variably (Wright, Grandjean
& McWhite 2013): some are treated as matters of fact, others
as matters of opinion. This pattern has been replicated in several
studies, and persists even when subjects are allowed to determine for
themselves which issues to assign to the moral domain, suggesting that
subjects do not think moral claims are uniformly objective



A question that remains is how to explain this variation: are people
being inconsistent? Are they tracking something besides the moral
question--perhaps the degree of consensus that exists about a
question? Further research may help shed some light on these issues,
but even if the questions are answered in the affirmative, the
realist's claim to capture folk morality is called into
question, since these experiments suggest that folk intuitions are
either not uniformly realist, or they are confused (and hence poorly
suited for a role in metaethical theorizing). Another response to
these findings is that they reveal a kind of folk metaethical
pluralism. For example, Michael Gill (2008, 2009) and Walter
Sinnott-Armstrong (2009) have suggested a noncognitivist treatment of
some areas of morality and cognitivism about others. This response is
under-motivated by empirical data, however, since such data shows at
most that our judgments about the extent to which moral claims
describe mind-independent facts is variable, and not that their
semantics itself varies. Nor does such data settle the question
whether our moral judgments are beliefs or another conative state:
while experimental data can reveal a role for emotion in moral
judgment, as discussed above, it does not show that in such cases
belief is absent. We will discuss limitations on experimental moral
philosophy in more detail in Section 5 below. For now, it seems that
data about folk realism are best viewed as undermining one of the most
commonly-cited sources of evidence for moral realism, namely, that it
captures our ordinary moral discourse and practice better than its
competitors. A further question, open to exploration, is whether an
anti-realist view might do better at capturing and explaining our folk
intuitions than realist competitors.


### 4.2 Moral Disagreement



As we saw at the beginning of this entry, some of the earliest
thinking in empirically-informed moral philosophy concerns moral
disagreement. Brandt and Ladd conducted in-depth investigations into
the moral codes of other groups, and some contemporary moral
philosophers have argued for continuing attention to the empirical
details of moral disagreement. This is partly due to the influence of
Mackie's (1977: 36-37) formulation of what he dubbed
'the argument from relativity' in terms of an inference to
the best explanation: the best explanation of the nature and
persistence of moral diversity, Mackie argues, is that our moral
judgments represent "ways of life," rather than
"perceptions, most of them seriously inadequate and badly
distorted, of objective moral values." Realists have tended to
respond to the argument by pointing to other possible explanations of
disagreement that are consistent with objectivity, such as mistakes
about the non-moral facts, irrationality, and failures of impartiality
and imagination (e.g., Brink 1984; Sturgeon 1988; Smith
1994; Shafer-Landau 2003; for an overview and analysis of realist
responses, see Loeb 1998).



Here it is useful to recall Brandt's admonition that "bare
information about intercultural differences" will not suffice to
settle the debate. Because the argument from disagreement turns, in
part, on both the existence of moral disagreement and the best
explanation for it, evaluating the prospects for the argument requires
attention to the empirical details of actual moral disagreements,
rather than conjecture about the outcomes of possible moral
disagreements. For example, Doris and Plakias (2008) discuss several
instances of cross-cultural moral disagreement, and assess the
prospects for applying what they call 'defusing
explanations' to these cases. A defusing explanation is one that
accounts for the disagreement in terms of a non-moral difference or an
epistemic shortcoming on the part of one or more disputant, thereby
showing that it is not, in fact, a moral disagreement. Their argument
and the experiments they cite are discussed in detail in the entry on
empirical moral psychology, so we will not discuss them in detail
here; for now, we will note that such explanations are difficult to
assess via survey methods alone. This is why it is especially helpful
to look to the anthropological record, as Oliver Curry et al. (2019)
do in a recent publication. Curry hypothesizes that morality comprises
stable, cooperative solutions to recurrent problems that can be
modeled as non-zero-sum games. There are a variety of such recurrent
problems, and game theory has established a suite of analytical tools
for diagnosing and solving them. Curry and his colleagues show that
such solutions are *always* seen as either morally good or
morally neutral in societies at various stages of development, from
small-band hunter gatherers to industrialized democracies. This
research suggests that philosophers may have greatly exaggerated the
extent of moral disagreement that actually exists.


### 4.3 Moral Language



One reason disagreement is a useful measure of objectivity is that the
impossibility of faultless disagreement is taken to be characteristic
of questions concerning objective matters of fact. That is, while we
might concede the possibility of faultless disagreements about matters
concerning the deliciousness of foods or the merits of a sports team,
when we disagree over moral issues, we think that there is a correct
answer and that therefore at least one disputant is getting things
wrong (for a discussion of the analogy between food and morality, see
Loeb 2003). To the extent that people judge a disagreement to be
faultless, we might think that they are evincing a kind of
anti-realism about the issue under dispute. This is yet another way
disagreement can bear on the realism/antirealism debate. Can
experimental evidence involving disagreement tell us anything about
the semantics of moral language?



One reason to think it can is that the very idea of faultless
disagreement strikes some as incoherent. In cases where one individual
thinks (or says) that pistachio ice cream is delicious and another
thinks (or says) that it is disgusting, we understand the two parties
as expressing their own personal preference. To explain the apparent
faultlessness of the dispute, we reinterpret their thoughts or
utterances as expressing something like, "pistachio ice cream is
delicious [disgusting] *to me*." Because the two parties
do not genuinely contradict one another, we need not say that one of
them is mistaken. Faultlessness is therefore supposed to be a point in
favor of the moral anti-realist, since it seems to imply that there is
no single content about which the parties disagree (and about which
one might be mistaken).



By contrast, realists claim that their view is better able to capture
our intuition that there is a genuine disagreement at stake when one
person says that stealing is wrong and another says that stealing is
not wrong. In these cases, realists argue, we have the intuition that
there really is a conflict, and only a theory on which moral language
involves attributing properties to acts and things, rather than
reporting or expressing speakers' attitudes, can capture this
intuition.



We have already seen some data bearing on this issue in our discussion
of folk realism above. The claim here is not about realism per se, but
about whether experimental evidence can give us insight into the
semantics of moral language, since our intuitions about whether there
is genuine faultlessness can tell us about whether there is a single
shared content between two utterances--a single proposition that
one party asserts and another denies--or whether the two
parties' utterances contain implicit relativizations. This has,
at least, been the assumption guiding much of the debate over
disagreement and its implication for moral semantics. In recent work,
however, John Khoo and Joshua Knobe (2018) have cast doubt on this
assumption; their experiments indicate that subjects do not see
disagreement as requiring exclusionary content--a single
proposition that one party accepts and the other rejects. Intuitions
about disagreement may thus not be as straightforwardly tied to moral
semantics as philosophers have thought: judgments that two individuals
genuinely disagree about some claim do not necessarily imply a single
shared content between the two speakers. This work is still in early
stages, but it reveals the complications involved in reading semantics
off disagreement.



A further challenge for attempts to experimentally investigate moral
semantics is the debate within antirealism between cognitivism and
noncognitivism. According to the cognitivist, ordinary moral sentences
are best understood as factual assertions, expressing propositions
that attribute moral properties (such as rightness or goodness) to
things (such as actions or characters). Noncognitivists (including
their contemporary representatives, the expressivists) hold that moral
language has a fundamentally different function, to express attitudes
or to issue commands, for example. While this debate seems ripe for
experimental investigation, the noncognitivist typically acknowledges
that their view is a reforming one. Furthermore, the semantics of our
terms may be opaque to ordinary users, to the extent that we cannot
read off semantics from intuitions but must investigate them
indirectly. Lastly, the cognitivist and noncognitivist can agree on a
number of empirical features of moral judgment and discourse; the
challenge for experimentalists is to find predictions that confirm one
view while disconfirming the other. This is a relatively new area of
investigation and, while not without challenges, ripe for
exploration.


## 5. Criticisms of Experimental Moral Philosophy



Experimental moral philosophy far outstrips what we have been able to
cover here, and many issues and areas of productive research have
barely been touched upon. For example, experimental evidence is
relevant to moral questions in bioethics, such as euthanasia,
abortion, genetic screening, and placebogenic interventions. Likewise,
experiments in behavioral economics and cognitive psychology are being
employed in asking moral questions about public policy (Bicchieri
& Chavez 2010; Bicchieri & Xiao 2009). We neglect these
issues only because of lack of space. In the few words remaining, we
explore some potential criticisms of experimental philosophy.


### 5.1 Problems with Experimental Design and Interpretation



As a young field, experimental philosophy suffers from various
problems with experimental design and interpretation. These are not
insurmountable problems (Machery & Doris 2017), and they are
problems faced by related fields, such as social psychology, cognitive
psychology, and behavioral economics.



One issue that has recently come to the fore is the problem of
*replication* (Romero
 2019).[14]
 Statistical analysis is not deductive inference, and the mere fact
that statistical analysis yields a positive result does not guarantee
that anything has been discovered. Typically, an experimental result
is only treated as "real" if its *p*-value
is at most .05, but such a value just
indicates, roughly, the probability that the observation in question
or a more extreme observation would have been made if the null
hypothesis were true. It is not the probability that the null
hypothesis is false given the
 observation.[15]
 So, even when statistical analysis indicates that the null hypothesis
is to be rejected, that indication can be erroneous, and the null
hypothesis might still be quite plausible. 



We should also expect other failures of replication because of a bias
built into the system of funding experimentation and publishing
results. Since experimentalists are reluctant to report (and even
discouraged by journal editors and referees from reporting) null
results (i.e., results where the *p*-value is more
than .05), for every published result there may be any number of
unpublished non-results (Rosenthal 1979).



Another worry is that simultaneously testing many intuition-probes can
lead unwary experimenters on fishing expeditions. Suppose an
experimental philosopher conducts an experiment with two conditions:
in the experimental condition, participants are primed with
deterministic ideas, while in the control condition they are not
primed one way or another. She asks participants twenty different
questions about their moral intuitions, for instance, whether there is
free will, whether malefactors deserve to be punished, whether virtue
deserves to be rewarded, and so on. She then makes pairwise
comparisons of their responses to each of the questions in an attempt
to figure out whether deterministic priming induces changes in moral
intuitions. She thus makes twenty independent comparisons, each at the
industry-standard 5% level. Suppose now for the sake of argument that
there is no effect--that all null hypotheses are true. In that
case, the probability that at least one of these tests will result in
a Type I error (rejecting the null hypothesis even though it is true)
is 64%. More generally, when an experimenter performs *n*
independent comparisons at the 5% level, the
probability of at least one Type I error is \(1-.95^n\). This problem
can be addressed by various procedures, most notably the Tukey method
and the Bonferroni
 method.[16]



Multiple testing without correction is a form of
p-hacking (Simmons, Nelson & Simohnson 2011).
"P-hacking" refers to a family of practices that increase
the probability of obtaining a significant result by capitalizing on
chance, such as dropping outliers, testing statistical models with and
without covariates, and uncorrected multiple testing. While p-hacking
might be surprisingly frequent in psychology (John, Loewenstein
& Prelec 2012), it appears rare in experimental
philosophy (Stuart, Colaco & Machery 2018). 



The best way to tell whether such a result carries any evidential
value is for the experiment to be replicated--preferably by
another research group. If a result cannot be robustly replicated, it
is probably a mirage. Such mirages have turned up to a disturbing
extent recently, as Daniel Kahneman has famously pointed out (Yong
2012; see also Wagenmakers et al. 2012). Kahneman proposed a
"daisy chain" of replication, where no result in
psychology would be published until it had been successfully
replicated by another prominent lab. This proposal has not yet been
(and may never be) instituted, but it has raised the problem of
replication to salience, and a related project has taken off. The
reproducibility project in psychology aims to establish the extent to
which prominent, published results can be
 replicated.[17]
 Experimental philosophers have followed suit with their own
replication project (see the Other Internet Resources). This work has
recently yielded encouraging fruit: a large collaborative replication
effort suggests that approximately 7 out of 10 experimental philosophy
results can be reproduced, whereas similar efforts show that less than
half of the results in biomedicine, economics, and psychology are
replicable (Cova et al. 2021, Other Internet Resources). On the other
hand, as discussed throughout this entry, many influential
experimental studies in moral psychology have failed to
replicate. 


### 5.2 Philosophical Problems



One might object that the real problem with experimental moral
philosophy is not with science, but with its relevance (or more
precisely, its irrelevance) to moral philosophy. The objection is that
moral philosophy is concerned not with how we are and what we do, but
with how we ought to be and what we ought to do. As such, it is a
normative enterprise, and is unaffected by empirical results. Science
is hard, but so is morality; if we fail to understand and live up to
the demands of the latter, that doesn't show a problem with our
moral theory but with our moral natures.



Experimental philosophers can agree with this objection, up to a
point. No one is suggesting that we read morality directly off survey
results. But, to return to the point with which we began, while
morality is normative, it is also essentially practical. Moral theory
is a theory about what we ought to do: a theory about how creatures
like us ought to conduct ourselves and interact with one another. A
morality completely divorced from our natures, that demanded acts
impossible from us, would surely be unacceptable. This is not just a
point about experimental philosophy; utilitarianism is sometimes
critiqued as making unrealistic demands of impartiality. Alongside the
famous proscription against deriving an *ought* from an
*is*, we also find the dictum that *ought implies can*.
The exact extent to which morality can be demanding without being
unrealistic is itself a philosophical question, and so experimental
moral philosophy works in conjunction with philosophical analysis; it
does not aim to eliminate it. Exactly how the two relate to each
other, and how empirical evidence will bear on and influence debates
in moral theory in the future, is a contested issue, but surely
traditional moral theory and experimental moral philosophy have much
to learn from one another (Doris, Machery & Stich 2017).



We need to proceed cautiously here. No one doubts that what we ought
to do depends on how things are non-morally. For example, the moral
claim that a given man deserves to be punished presupposes the
non-moral fact that he committed the crime. It should come as no
surprise, then, that experimental evidence might be relevant in this
way to morality. Whether experimental evidence is relevant to
discovering the fundamental moral principles--those meant to be
put into action one way or another depending on how the world is
non-morally--is still subject to debate.



Another version of this argument says that fundamental moral
philosophical principles are, if true at all, necessarily true, and
that empirical research can establish at best only contingent
 truths.[18]
 But if fundamental moral theories are necessary, then they are
necessary *for creatures like us*. And one thing that empirical
investigation can do is to help establish what sorts of creatures we
are. Imagination needs material to work with. When one sits in
one's armchair, imagining a hypothetical scenario, one makes a
whole host of assumptions about what people are like, how
psychological processes work, and so on. These assumptions can be
empirically well or poorly informed. It's hard to see why anyone
could doubt that being well informed is to be preferred. Likewise
it's hard to see how anyone could doubt the relevance of
experimental evidence to better grounding our empirical assumptions,
in this case our assumptions relevant to moral philosophy. Exactly how
experimental--or more broadly, empirical--evidence is
relevant, and how relevant it is, are at present hotly contested
matters.