## 1. A Psychological Capacity Dedicated to Norms



Norms are the rules of a group of people that mark out what is
appropriate, allowed, required, or forbidden for various members in
different situations. They are typically manifest in common behavioral
regularities that are kept in place by social sanctions. From an early
age, humans see certain behaviors, contexts, and roles as governed by
norms. Once a person adopts a norm, it functions both as a rule that
guides behavior and as a standard against which behavior is evaluated.
Moreover, individuals typically become motivated to enforce the norms
they adopt, and so to participate in regulative practices such as
punishment and the ascription of blame. Such practices in turn help
stabilize the community's social arrangements and the norms that
structure them. Norms are often classified into kinds or
subcategories, with common examples including moral, social,
conventional, epistemic, aesthetic, and organizational norms. The
correct or theoretically most useful way to distinguish and taxonomize
kinds of norm is the subject of much debate, but one that will be set
aside here (see O'Neill 2017 for a review, Kelly forthcoming
for discussion). Rather, this section will sketch a general overview
of the conceptual space common to cognitive-evolutionary work on the
psychology of norms, and later sections will elaborate on its
contents, locating different claims and specific theories within
it.



An idea central to work on the psychology of norms is that human minds
contain a *norm system* of some kind, a set of psychological
mechanisms dedicated to handling information and producing behaviors
relevant to norms. Such mechanisms feature in an explanatory strategy
common throughout psychology (R. Cummins 2000). In this case,
theorists appeal to different properties of the norm system to help
account for different aspects of a complex capacity for norm-guided
behavior--a capacity to "do" norms. This capacity is
characterized by a broad but distinctive pattern of behavior: when
faced with norm relevant stimuli, typically centered on other
peoples' actions or their own, along with other cues concerning
the context of those actions and the roles of the actors, individuals
exhibit a robust and multifaceted type of response that is centered on
conformity and punishment. Taken together, the responses of
individuals aggregate up to produce stabilizing group-level effects on
patterns of collective social organization. The complexity and
robustness of the individual capacity suggests the operation of
dedicated psychological machinery--a norm system--which
sensitizes humans to certain social stimuli (behavior, contexts,
roles) and reliably produces the coordinated facets (physiologically,
inferentially, behaviorally) of the characteristic response.



This picture raises the question of *how* it is that humans are
able to spontaneously and reliably track norm-relevant features of
their world, infer the rules which govern it, and bring those rules to
bear on their own and others' behavior. It also calls for a
psychological answer, one that sheds light on what mediates the
stimuli and the response. By analogy, an automobile is capable of
acceleration--it reliably speeds up in response to the depression
of the gas pedal--but one needs to "look under the
hood" to see what sort of mechanisms are reliably translating
that kind of input into that kind of output. Moving from the
acceleration of a car to the norm-guided activity of a person,
cognitive-evolutionary approaches posit and investigate the
psychological machinery that is responsible for translating certain
kinds of social inputs into the kind of behavioral outputs associated
with norms. This strategy--of positing psychological mechanisms
that mediate stimulus and response--is supported by a now
familiar way of understanding the mind as an information processing
system. The inputs under consideration are treated as information,
which is routed and processed by a suite of psychological mechanisms
and finally translated into behavioral outputs. Those focused on the
psychology distinctive of normative cognition have posited the
existence of this kind of dedicated package of mechanisms, and have
investigated different possibilities about its nature.



To introduce a couple terms of art, accounts of psychological
capacities often aspire to provide both a *proximate
explanation* and an *ultimate explanation*. Where proximate
explanations try to answer, "How does it work?", ultimate
explanations try to answer, "How did we come to be like
this?" This distinction originates in biology (Mayr 1961; Ariew 2003), but is
applicable to behavioral and psychological traits as well (Griffiths
2007). Central to proximate explanations in these latter contexts are
the models of the psychological processes that underlie specific
capacities. After identifying a relatively complex ability, that
ability is explained in terms of the operation and interaction of a
set of relatively simpler underlying component mechanisms. Thus,
proximate explanations of norms aim to show how human individuals are
psychologically capable of the rich array of activity associated with
norm-guided behavior by identifying the component parts of the norm
system and describing how they operate.



*Ultimate explanations*, on the other hand, aim to explain the
likely origins of different traits. It is now common for the cognitive
sciences to make extensive use of evolutionary theory, taking what is
known about the environments and selective pressures faced by
ancestral populations and using it to help inform hypotheses about
minds (Barkow, Cosmides, & Tooby 1992). Central to many of the
ultimate explanations proposed by researchers interested in the
psychology of norms are the adaptive challenges raised by collective
action and large-scale cooperation (Gintis, Bowles, et al. 2005; Boyd
& Richerson 2005b; N. Henrich & J. Henrich 2007; Tomasello
2009). For the sake of clarity, it is helpful to remember that these
two styles of explanation are analytically distinct, but that
proximate and ultimate explanations for a given trait will ideally be
complementary and mutually reinforcing. Thus, evolutionary accounts of
norm cognition can inform and constrain proximate models, and vice
versa.



The psychological focus of cognitive-evolutionary approaches to norms
gives them a fairly clear research agenda. It is worth noting,
however, that while questions about the nature of norms are relevant
to a range of debates in philosophy (and beyond), work on the
psychology of norms is not primarily driven by one particular
*philosophical* tradition or debate. Rather, those focused on
normative *psychology* are typically guided by a set of general
issues concerning human nature: the structure and distinctive features
of human minds, the pathways of human evolution that produced them,
and the commonalities and differences between human minds and
behaviors, on one hand, and those found in non-human species, on the
other (Tomasello 1999; Richerson & Boyd 2005; Tooby & Cosmides
2005; J. Henrich 2015; Vincent Ring, & Andrews 2018). One upshot
of this is that theorists draw on the full range of explanatory
resources made available by contemporary cognitive science. Thus,
these accounts of normative cognition are not constrained by
folk-psychological explanations of behavior, and so are free to posit
and appeal to psychological mechanisms, states, and processes that
need not bear much resemblance to beliefs and desires, credences and
preferences, conscious deliberation and explicit inference.



This entry is organized around research whose focal point is the
psychology distinctive of normative cognition. However, *any*
discussion of norms and norm-guided behavior will involve, tacitly or
otherwise, *some* picture or other of agents and the
characteristics that make them responsive to normative influence. Some
begin with analytic formalizations of the kinds of agents and mental
states assumed by common sense folk psychology, and use these
formalizations, along with various refinements, to account for
different norm related phenomena. These fall beyond the scope of this
entry, but see especially Bicchieri, Muldoon, and Sontuoso (2018) for
an overview of such approaches (also see Bicchieri 2006, 2016; Brennan
et al. 2013; Conte, Andrighetto, & Campenni 2013; Hawkins,
Goodman, & Goldstone 2019; cf. Morris et al. 2015). It is also
worth noting that cognitive-evolutionary approaches are sometimes
presented as importantly different from classic rational choice
approaches to human decision and social behavior (Boyd & Richerson
2001; Henrich, Boyd, et al. 2001, 2005). Whether these are
genuinely distinct alternatives remains unclear (Elster 1991, cf.
Wendel 2001), but those who make the case typically point to a growing
body of evidence that suggests humans rarely approximate the
unboundedly rational, purely self-interested agents of classical
economics (Gigerenzer & Selten 2001; Kahneman 2011, cf. Millgram
2019, Other Internet Resources). To illustrate, participants in
one-time, anonymous cooperation games have been observed to routinely
cooperate, even when they are made explicitly aware of their anonymity
and the fact that they will play the game just once (Marwell &
Ames 1981; see Thaler 1992 for a review). Those sympathetic to
cognitive-evolutionary approaches to norms have an explanatory
template for this kind of finding ready at hand, and will construe
participants' behavior as motivated by their norm systems and
the pro-social norms that they have internalized.



With the expanded repertoire of psychological entities at their
disposal, explanations that appeal to a psychological capacity
dedicated to norms also appear well suited to capture the kinds of
dissonance and dissociation that can occur between individuals'
attention, implicit categorization, and normative motivation, on the
one hand, and their explicit beliefs and avowed principles, on the
other. A person may, for example, explicitly endorse feminism and
sincerely wish to extinguish the sexist norms and expectations he has
about women, but nevertheless find himself monitoring the social world
through the lens of those sexist norms, and experiencing recalcitrant
motivation to enforce and comply with them (cf. work on implicit
biases Brownstein & Saul 2016). In short, on this kind of picture
different psychological systems that comprise an individual's
mind (perhaps the norm system and the practical reasoning system) can
work independently from, and be at slight odds with, each other.



Several more specific features that appear distinctive of normative
cognition have drawn considerable attention from psychological
researchers. These include the propensities to *acquire* norms,
to *comply* with norms, and to *enforce* norms. When a
person is born into or otherwise enters a community, she needs to be
able to identify and extract information about the broad assortment of
norms that shape it, who different norms apply to and when, and what
the consequences of breaking them are. She must be able to see some
behaviors *as* normatively regulated, and then to infer what
the governing rule is. Learning how to do this is sometimes supported
by intentional pedagogical behavior by her mentors (Sterelny 2012),
but need not be (Schmidt, Rakoczy, & Tomasello 2011). Gaining
knowledge of the rules is not where it ends. Individuals rarely just
observe such social activities, but rather come to competently
participate in them. To do this, a person typically learns to behave
in compliance with the norms she identifies as applying to herself;
acquiring those norms results in their coming to guide her own
conduct. Finally, prevalent norms and standards of conduct are
collectively maintained by a community when its members enforce them,
punishing those who fail to follow the rules. Enforcement and
punishment are broad categories, and can include correcting, withholding cooperation,
communicating disapproval through body language or explicit criticism,
ostracizing or gossiping about norm violators, or even physical
violence. Thus, individuals become responsive to norms and the social
pressure by which they are enforced, and motivated to apply social
pressure to others who transgress.



Further questions arise about each of these propensities. One cluster
of questions concerns the details of acquisition: what sort of
perceivable cues are salient to the norm system, prompting a person to
perceive a behavior, context, or role *as* normatively
governed? And once a norm is identified, what causes a person to
internalize it? Perhaps the merely statistical fact that most people
behave the same way suffices in some cases, while in others a
sanctioning response may be required to activate the acquisition
process. A second family of issues concerns motivation: is norm-guided
behavior typically driven by intrinsic or instrumental motivation?
People may comply with a norm for its own sake, simply because it is
felt to be the right thing to do. They may also, however, obey a norm
merely in order to avoid punishment and blame. Some behaviors may be
driven by both kinds of motivation. Similar and perhaps more puzzling
questions arise about the psychological roots of people's
motivation to punish others who violate norms. A third family of
questions can be framed in terms of innateness: to what degree are the
mechanisms responsible for norm cognition innately specified or
culturally acquired? Aside from the mechanisms, is any of the
content--any of the norms themselves--innately
specified?



Cognitive-evolutionary approaches to norms treat these as empirical
questions, and thus see value in, and aspire to be sensitive to, a
wide range of evidence. Before looking more closely at some of that
evidence however, it will be useful to be familiar with the types of
theoretical tools researchers typically use to generate and interpret
it.


### 1.1 Background: Evolution and Ultimate Considerations



A working hypothesis of cognitive-evolutionary approaches is that the
psychological mechanisms underlying norm cognition are evolved
adaptations to important selection pressures in human evolutionary
history (Richerson & Boyd 2005; Sripada & Stich 2007,
Tomasello 2009; Chudek & Henrich 2011; Kelly & Davis 2018, cf.
Cosmides & Tooby 1992). Even if a detailed proximate account were
already available, other questions could be asked about the provenance
of the norm system: how--that is, due to which evolutionary
factors--did human minds come to be equipped with these
psychological mechanisms? To what adaptive problem or problems was
normative cognition a solution? What selection pressures were
primarily responsible for the evolution of a norm system, and what
phylogenetic trajectory did that evolution take? A brief summary of
the types of answers currently on offer to these questions provides
useful context for the discussion of proximate explanations that
follows.



A fairly uncontroversial background tenet of the received view is that
humans are extraordinarily social animals, and that our hypertrophied
abilities to learn from and cooperate with each other are key to what
set us apart from our closest primate ancestors and other hominid
species. A crucial difference is thought to be that human capacities
to imitate and learn from each other became powerful enough to sustain
*cumulative culture* (Tomasello 1999; J. Henrich &
McElreath 2003, Laland 2017). Culture is understood as information
that is transmitted between individuals and groups via behavior,
rather than processes like genetic transmission (Ramsey 2013).
Beliefs, preferences, norms, skills, techniques,
information-containing artifacts, etc., are passed from individual to
individual, and thus across populations and between generations,
mainly by *social learning* (Mathew & Perreault 2015). For
example, development of the set of techniques and skills associated
with throwing spears, or the knowledge and tools enabling the
controlled use of fire, have been tied to increases in opportunities
for social learning provided by expanding social networks and more
complex forms of social activity (Thieme 1997; Gowlett 2006). Culture
is *cumulative* in the sense that the body of information in
the cultural repository does not remain static, but can itself grow
larger and more complex. Grass huts evolve into wood-frame houses,
then brick buildings, and eventually skyscrapers. Tribal leaders
evolve into kings, then emperors, then prime ministers. Simple sets of
norms evolve into more complicated informal institutions, then
byzantine formalized legal codes. As each generation adds its own new
innovations, discoveries, and improvements, functional sophistication
is accumulated in cultural traits in much the same way as it is
accumulated in genetic traits.



This general evolutionary outlook gives reason to think that as human
groups increased in size, they also grew in their capacity to carry
more culture and produce more cultural innovations (Kline & Boyd
2010; J. Henrich 2015: chapter 12), though the causal relationship
between population size and cultural complexity remains controversial
(Fogarty & Creanza 2017, cf. Vaesen et al. 2016). As cultural
innovations continued to accumulate, they allowed humans to more
significantly control and reshape the environments in which they
lived. Such transformations also reshaped the environments inhabited
by subsequent generations, thus shifting the contours of the physical,
social, and informational niches in which they evolved. Such changes,
in turn, created a range of new selection pressures, many of which
favored bodies, brains, and minds better equipped for sociality and
cultural inheritance. Researchers continue to develop and debate the
merits of different conceptual tools with which to conceive of this
kind of evolutionary dynamic (Tomasello 1999; Laland, Odling-Smee,
& Feldman 2001; Laland, Odling-Smee, & Myles 2010; Sterelny
2003, 2012; Richerson & Boyd 2005; Tennie, Call, & Tomasello
2009; Boyd, Richerson, & Henrich 2011, J. Henrich 2015; Boyd
2017).



Humans are able to inhabit a wide range of environments, and socially
transmitted information--as opposed to innately specified and
biologically transmitted information--is particularly useful in
the face of ecological and social variation (Richerson & Boyd
2013). Information about which plants in various environments are
edible and which are toxic has straightforward adaptive advantage.
Information about what kinds of norms prevail in various social
environments is also important, and knowing it allows individuals to
smoothly participate in their community and coordinate with other
members in an array of collective activities that ranges from
producing food and raising children to responding to threats and
dealing with outsiders (Chudek & Henrich 2011). While different
types of *cultural variants* can be useful in different ways,
not all socially transmittable information is equally valuable, and
individuals are not indiscriminate social learners. Theorists posit
that human minds evolved to contain a number of social learning
*biases* or *heuristics* that help facilitate more
selective learning. These influence which, of the many cultural
variants to which an individual is exposed, she will actually adopt
for herself. Two heuristics appear to be particularly important in
amplifying the advantages of a system of cultural inheritance. One is
a *conformity* bias, which prompts individuals to adopt those
cultural variants that have been adopted by most others in their
community (Muthukrishna, Morgan, & Henrich 2016), and another is a
*prestige* bias, which sensitizes individuals to hierarchy and
status, prompting them to model their behavior on those who have
achieved success and high social rank (J. Henrich & Gil-White
2001; Cheng et al. 2012; Maner 2017). In addition to these two,
researchers have posited other learning biases that can influence norm
acquisition, including one that makes information about norms easier
to remember than other, non-normative information about behavior
(O'Gorman, Wilson, & Miller 2008).



Culture looms increasingly large in evolutionary explanations of human
ultrasociality, i.e., our species' ability to cooperate on a
remarkably large scale (Tomasello 2009, 2016; Richerson 2013; though
see Hagen & Hammerstein 2006; Burnham & Johnson 2005 for
alternative views, and Sterelny, Calcott, & Fraser 2013 for
broader context on the evolution of cooperation). An increasingly
prominent idea is that explaining the full range of behaviors involved
in human sociality will require some appeal not just to culture in
general, but to culturally transmitted norms and institutions in
particular (Mathew, Boyd, & van Veelen 2013). Some have taken the
significance and complexity of the adaptive challenges posed by
large-scale cooperation to have implications for human psychology,
arguing from these grounds that human minds have a capacity specific to
norms (Chudek, Zhao, & Henrich 2013), which may have evolved in
tandem with our capacities for language (Lamm 2014). Others argue
further that cultural group selection, generated by various forms of
competition between cultural groups like communities, tribes, clans,
and even nations, has contributed to the spread of more effective
cooperative norms (Turchin 2018; Richerson, Baldini, et al. 2016,
though see Krasnow et al. 2015). On such views, these kinds of
selective pressures further remodeled human social psychology,
supplementing more evolutionarily ancient social instincts to form
what have been called tribal social instincts (Richerson & Boyd
2001; Boyd & Richerson 2008; Richerson & Henrich 2012). This family of
evolutionarily recent "instincts" is posited as including
a capacity for norms, but also other psychological features thought to
refine norm-guided behavior in various ways, including sensitivities
to markers of tribal membership and the boundaries between ethnic
groups (McElreath, Boyd, & Richerson 2003) and social emotions
like guilt, pride, and loyalty.


### 1.2 Psychology and Proximate Explanations: Theoretical Tools and Dimensions



The theoretical toolkit common in the cognitive and behavioral
sciences affords several key dimensions along which different
theorists stake out and explore more specific positions about
normative psychology. Capacities like the one for norms are understood
as complex in the sense that they are subserved by a number of
simpler, interrelated processes and subsystems. Such complex systems
are usefully analyzed by reference to those simpler ones that comprise
them. When used in psychology, this general method of analyzing
complex systems by appeal to the character and interactions of their
component parts often takes the form of what has been called
homuncular functionalism (Lycan 1990), where it is paired with the
metaphysical doctrine of functionalism about the mind. This, briefly
stated, is the view that mental states and processes are functional
states, identified by the characteristic role they play in the
psychological system of which they are a part (Putnam 1963, 1967;
Fodor 1968; Levin 2004 [2018]). Dennett, an early proponent of
homuncular functionalism, urged psychologists to follow a method
parallel to that used in artificial intelligence research:



> 
> 
> The AI researcher *starts* with an intentionally characterized
> problem (e.g., how can I get a computer to *understand*
> questions of English?), breaks it down into sub-problems that are also
> intentionally characterized (e.g., how do I get the computer to
> *recognize* questions, *distinguish* subjects from
> predicates, *ignore* irrelevant parsing?) and then breaks these
> problems down further until he reaches problem or task descriptions
> that are obviously mechanistic. (Dennett 1978: 80)
> 
> 
> 



An important step in any explanation is delineating the target
phenomena itself. In cognitive science, this step often takes the form
of characterizing a capacity via task analysis, which amounts to
identifying and distinguishing the *tasks* or functions that
are performed in exercising the relevant capacity. For example, some
tasks currently thought to be central to the functioning of a norm
system include those mentioned above: acquisition, compliance, and
enforcement. Another step is concerned with modeling the
*psychological mechanisms* responsible for carrying out those
tasks: the typical algorithms and patterns of information processing
that perform those functions. The final step in completing a full
account of a capacity would be an explanation of how those mechanisms
and algorithms are *implemented* and thus realized in the
person's physical, chemical, and biological structures (see Marr
1982 for the classical discussion of these different levels of
explanation).



While experimental and other behavioral evidence can help to more
directly characterize a capacity and identify its associated tasks,
many theoretically important issues have to do with determining what
kind of psychological mechanisms should be posited to account for
them. Theorists defending different views might hypothesize different
mechanisms that underpin a particular capacity, or give different
accounts of how a mechanism performs its function. They can also agree
or disagree about how the relevant mechanisms are organized,
developing different accounts of their proprietary algorithms, and the
types of causal and informational links each bears to each other and
to other elements of a person's overall psychological economy
(perceptual systems, short term memory, action production systems,
etc.).



Within this conceptual space there are number of prominent dimensions
along which accounts might vary. The following list of such dimensions
is not exhaustive, but it gives a sense of some of the most
significant ones. The psychological mechanisms posited by different
proximate accounts of a norm system can differ with respect to


1. Whether and to what extent they are fast, automatic, intuitive,
non-conscious, or otherwise fit the description of "type
1" cognition, or are slow, controlled, effortful, conscious, or
otherwise fit the description of "type 2" cognition
2. Whether and to what extent they bear the markings of modularity,
i.e., are cognitively impenetrable, informationally encapsulated,
domain specific, etc.
3. Whether and to what extent they require or are subject to
voluntary control
4. Whether and to what extent mechanisms and their content are
universal aspects of human psychological nature, or instead exhibit
variation across habitats and cultures
5. Whether and to what extent the mechanisms and their content are
innate, genetic adaptations, or are instead socially learned and
culturally transmitted
6. Whether and to what extent the motivation associated with the
mechanisms is intrinsic or instrumental



The first dimension concerns a distinction between *type 1* and
*type 2* cognitive processes made by dual processing and dual
systems theories (see Frankish 2010 for a review, Cushman, Young,
& Greene 2010). Type 1 processes are typically characterized as
"fast and frugal," intuitive, heuristic processes which
deliver "rough-and-ready" responses (Gigerenzer et al.
2000). These processes take place automatically and unconsciously and
are prone to error, but they make up in speed and resource-efficiency
what they lack in precision. Type 2 processes, by contrast, are
typically characterized as slower, rule-based, analytical processes
which require more concentration and cognitive effort, take place
consciously, and deliver more precise responses.



The second dimension concerns the view that the mind is, to some
degree, made up of modules: psychological mechanisms that are
informationally encapsulated, fairly autonomous, automatic, and
domain-specific (Fodor 1983; Carruthers 2006; Robbins 2009 [2017]).
Modules are informationally encapsulated in the sense that they are
insensitive to information present in the mind but not contained
within the mechanism itself, leaving their internal processes
unaffected by, for example, what the person reflectively believes or
prefers. A related property is cognitive impenetrability. This
captures the fact that the information and processes inside a module
are themselves inaccessible to central systems, such as those involved
in introspection or deliberation. Although it is often possible to
consciously consider the output of a modular mechanism, the endogenous
processes responsible for producing that output will remain opaque to
direct introspection (Carruthers 2011).



Turning to the third dimension, it should be clear how commitments
along the first two dimensions could support different views about the
extent to which normatively governed expectations and behavior require
or are susceptible to voluntary control. If the processes subserving
the capacity for norms are to some degree automatic and unconscious,
and are insensitive to changes a person makes to her explicit beliefs,
judgments, or volitions, those processes would be able to affect her
behavior without the need of any guidance from her will, and could
help produce behaviors and judgments that oppose it. Research on
implicit bias may provide useful resources for thinking about the
relationship between normative cognition and voluntary control. Recent
work sheds light on what kind of intervention strategies are effective
(Lai et al. 2014; Devine et al. 2012), and suggests that deliberate
cognitive effort and voluntary control can, under certain conditions,
override the influence of implicit and automatic cognition. Turning to normative cognition, research
suggests that self-control may be required to violate a norm one has
internalized, such as the norm against breaking promises (Baumgartner
et al. 2009), but the details remain unclear (Peach, Yoshida, &
Zanna 2011; Yoshida et al. 2012; also see Kelly forthcoming for
discussion of differences between internalized and avowed norms).



The fourth and fifth dimensions are where the traditional
nature/nurture debate plays out with respect to norms and normative
psychology. It is part of the standard account of modules that they
are innate in the sense that they will develop in more or less the
same way in normal humans, irrespective of cultural setting. Advocates
of so-called Evolutionary Psychology, one especially visible way of
applying evolutionary thought to human behavior, have embraced the
idea of modules, even arguing that human minds are "massively
modular", i.e., composed exhaustively or almost entirely of
modular psychological mechanisms (Barkow, Cosmides, & Tooby 1992;
Samuels 1998; Carruthers 2006). On such a view, normative psychology
will also be modular in many respects. One way to develop this idea
would be to make the case that all human cultures are structured by
some set of norms or another, suggesting the presence of modular
cognition. The ways in which norms differ from one group to the next
might then be explained by appeal to an *evoked culture* model
(Tooby & Cosmides 1992, though see Sperber 1996 for a different
account of the relationship between modular cognition and culture).
According to this model, the norm-guided behaviors found across
cultures would be construed as innately constrained, rooted in
endogenous mental form and content of the "cognitive adaptations
for social exchange" common to all human minds. Normative
variation, then, would be explained by appeal to the fact that
different groups live in different circumstances, and variation in the
external conditions they face evokes different subsets of the set of
all norms and norm-governed behaviors made possible by the norm
system. Such a view has been suggested but not yet fully worked out
(though see Buchanan & Powell 2018). An alternative family of
views puts the ideas of innateness and domain-specificity to different
uses (Fessler & Machery 2012). These, which have been more
developed for normative psychology, depict humans as having an innate
capacity dedicated to acquiring and performing norms, but whose
underlying mechanisms contain little if any innately specified
content. No particular norms would be innate on such a view; rather,
the capacity (perhaps together with some set of learning biases)
guides acquisition in its specific domain, and thus equips individuals
to easily internalize whatever norms are present in her local social
environment (Boyd & Richerson 2005a; Sripada & Stich 2007;
Chudek & Henrich 2011; Kelly & Davis 2018).



A general alternative to these kinds of nativist, modular views has
recently been developed in more detail. It holds that psychological
mechanisms bearing many characteristics of type 1 processes might be
learned *cognitive gadgets* rather than innate cognitive
instincts or modules. On this account, a complex capacity--for,
say, reading and writing or playing chess--is still underpinned
by a number of relatively integrated psychological mechanisms and
routinized processes, but these mechanisms themselves (as opposed to
merely the content they process) are fashioned and bundled together by
cultural evolution. These packages of skills, once available in the
group's cultural repertoire, can then be acquired by individuals
via domain general learning processes (Heyes 2018). The idea of a
cognitive gadget provides a promising new theoretical option for
psychology in general. Its advocates have not yet systematically
addressed the question of whether it best captures the capacity for
norms, however (though see Sterelny 2012 chapter 7 for a discussion
that anticipates this line of thought).



Others interested in moral cognition more generally--which
outstrips work on norm-guided behavior to include work on the
psychology of altruism, well-being, character and virtue, moral
emotions, intentional versus unintentional action, and so
forth--have sought to develop an analogy between Chomskyan
theories of language acquisition and use, on one hand, and the
acquisition and application of moral rules, on the other (Mikhail
2007, 2011; Dwyer, Huebner, & Hauser 2010; Hauser, Young, &
Cushman 2008; Roedder & Harman 2010). This approach is generally
nativist, positing a universal moral competence that guides learning
specifically in the domain of morality, and contains enough innately
specified structure to account for the putative poverty of moral
stimulus that children face when attempting to learn the norms that
prevail in their local environment (see Laurence & Margolis 2001
for discussion of poverty of the stimulus arguments in cognitive
science). Some advocates also suggest that in addition to information
specifying the structure of the mechanisms dedicated to acquiring and
processing moral norms, a few particular norms themselves may also be
included as part of the innate moral capacity, perhaps norms against
incest or intentionally causing harm (e.g., Mikhail 2007,
2011). Others have criticized this view (Prinz 2008; Sterelny 2012),
but only recently has a more detailed positive account of rule
acquisition begun to be developed. Central to this newly emerging
empiricist alternative is the idea that individuals are rational rule
learners, but they rely on domain general learning strategies to
acquire norms from their social environment, rather than on an
innately specified, domain specific moral competence (Gaus &
Nichols 2017; Ayars & Nichols 2017, 2020; Nichols
forthcoming.)



The sixth and final dimension concerns motivation. Especially in light
of the roles that punishment and reward play in the stabilization of
group-level patterns of behavior, an initially plausible idea is that
normative motivation is *instrumental* (for discussion see Fehr
& Falk 2002). On such views, an individual conforms to a norm in
order to receive some benefit, or to avoid reprimand, or because she
wants to behave in the way she thinks others expect her to behave.
Such motivation would be instrumental in the sense that people obey
norms merely as a means to some further end that more fundamentally
drives them; in counterfactual terms, remove the external reward,
punishment, or social expectation, and the individual's norm
compliant behavior will disappear along with it. Those who explore
this kind of account have recently emphasized the role of
psychological states like conditional preferences, together with
2nd order social beliefs, i.e., people's beliefs
about other people's expectations, and people's beliefs
about other people's beliefs about what should be done (see
Bicchieri, Muldoon, & Sontuoso 2018 for discussion of such a
family views).



Other accounts construe normative motivation as *intrinsic*
(Kelly & Davis 2018; Nichols forthcoming,
especially chapter 10). On such a
view, once a norm is acquired and internalized, it typically becomes
infused with some kind of non-instrumental motivation. People will be
motivated to comply with and enforce a such rule for its own sake, and
experience an impetus to do so that is independent of external
circumstances or the perceived likelihood that they will receive
social sanctions even if they flout the norm. Intrinsic motivation
does not imply unconditional behavioral conformity, of course. For
example, a person may feel the intrinsic pull of a norm that
prescribes leaving a 20% tip, but still choose to override it and
instead act out of material self-interest, stiffing the waiter. This
second family of accounts raises a broader set of questions about the
psychological nature of normative motivation, and if and how it might
be special. Is normative motivation best treated as a primitive, its
own *sui generis* psychological category? Or is it better
construed as being generated by more familiar psychological elements
like desires, emotions, drives, or other types of conative states,
posited on independent grounds, that are recruited to work in
conjunction with normative psychology? (see Kelly 2020 for
discussion)



An early and influential account of the psychology of norms given by
Sripada and Stich (2007) illustrates how these kinds of theoretical
pieces might be put together. The preliminary model posits two innate
mechanisms, a *norm acquisition mechanism* and a *norm
execution mechanism.* The functions or tasks of the norm
acquisition mechanism are


1. to *identify behavioral cues* indicating the existence of
a norm
2. to *infer the content* of that norm, and finally
3. to *pass information* about that content on to a norm
execution mechanism



The tasks of the norm execution mechanism, on the other hand, are


1. to *encode* and *store* those norms passed along to
it by the acquisition system in a *norm database*, which may
have some proprietary processes for reasoning about the contents
represented therein
2. to *detect* cues in the immediate environment that
indicate if any of those norms apply to the situation, and if so to
whom
3. to generate motivation to *comply* with those norms that
apply to oneself,
4. to generate motivation to *punish* those who violate norms
that apply to them



Sripada and Stich provide an initial pictorial representation:



![a diagram: link to extended description below](drawing-plain.svg)

Figure: Sripada & Stich 2007: 290,
figure redrawn.
 [An
 extended description of the figure
 is in the supplement.]




The acquisition and execution mechanisms themselves are posited as
innate, but are highly sensitive to the local social setting in which
an individual develops. As described above, this bifurcation into
innate psychological architecture, on the one hand, and socially
learned normative content, on the other, is taken to explain why the
presence of norms is culturally universal, whereas the behaviors,
roles, and social arrangements governed by those norms exhibit
variation. In addition, the model depicts the operation of many
components of the norm system as "automatic and
involuntary" (Sripada & Stich 2007: 290), but takes no stand
on particular processes or more granular characteristics associated
with modularity or dual processing. Finally, the model is designed to
accommodate evidence suggesting that when a norm is acquired and
represented in the database it thereby gains a distinctive kind of
motivational profile. Specifically, this profile construes normative
motivation as


1. intrinsically as opposed to instrumentally motivating
2. both self- and other-oriented
3. potentially powerful



On this account, normative motivation has the third property in the
sense that in some cases it is capable of overpowering even fairly
compelling motivations that pull in conflicting directions; extreme
examples include suicide bombers overriding their instincts for
self-preservation, or other fanatics who expend significant resources
to enforce their favored norms on others. The self- and
other-directedness of normative motivation captures the idea that the
norm system produces motivation to keep one's own behavior in
compliance with a norm as well as motivation to enforce it by
punishing others who violate it.



Finally, the model depicts normative motivation as intrinsic in the
usual sense that people comply with norms as ultimate ends, or for
their own sake. Sripada and Stich suggest that intrinsic motivation
helps explain a property of norms they call "independent
normativity". This marks the fact that norms can exert reliable
influence on people's behavior even when those norms are not
written down or formally articulated in any formal institution, and
thus not enforced via any official mechanisms of punishment and reward
(also see Davidson & Kelly 2020). They also discuss motivation and
independent normativity in terms of an "internalization
hypothesis" drawn from sociology and anthropology, and suggest
that the idea of internalization can be interpreted in terms of their
model. On this story, a person has internalized a norm when it has
been acquired by and represented in her norm database. The
internalization hypothesis can then be construed as a claim that
internalized norms are intrinsically motivating for the simple reason
that it is a fundamental psychological feature of normative psychology
that once a norm has been acquired, delivered to, and represented in a
person's norm database, the norm system automatically confers
this distinctive motivational profile on the norm. Being accompanied
by self- and other-directed intrinsic motivation is part of the
functional role a rule comes to occupy once it is represented in the
database of a person's norm system--when it is
"internalized"--in something analogous to the way
that being accompanied by avoidance motivation and contamination
sensitivity is part of the functional role a cue comes to occupy once
it is represented in a person's disgust system (Kelly 2011; also
see Gavrilets & Richerson 2017 for a computational model exploring
the evolution of norm internalization and the kinds of selective
forces that may have given normative psychology this intriguing
characteristic).


## 2. Empirical Research



The explanatory strategies and theoretical toolkit of the cognitive
sciences have been used to guide and account for an enormous range of
empirical work. Cognitive-evolutionary approaches to normative
psychology are likewise interdisciplinary, and aspire to
accommodate empirical research done on norms by anthropologists,
sociologists, behavioral economists, and developmental, comparative,
and other kinds of psychologists. This section provides a sampling of
the sorts of findings that have been marshalled to illuminate
interesting aspects of norm-guided behavior and support different
claims about normative cognition.


### 2.1 Sociology, Anthropology, and Cultural Psychology



As noted above, the ethnographic record indicates that all cultures
are structured by norms--rules that guide behavior and standards
by which it is evaluated (Brown 1991). Evidence also suggests that
norms are fairly evolutionarily ancient, as there is little indication
that the capacity for norms spread from society to society in the
recent past. Anthropologists also have shown that norms governing,
e.g., food sharing, marriage practices, kinship networks, communal
rituals, etc., regulate the practices of extant hunter-gatherers and
relatively culturally isolated groups, which would be unlikely if
norms were a recent innovation (see J. Henrich 2015 for a review).
Much attention, however, has been given to the ways in which the
prevailing sets of norms vary between cultures (House, Kanngiesser, et
al. 2020; cf. Hofstede 1980, 2001) and the manner in which packages of
norms develop and change over time within particular cultures (Gaus
2016, Schulz et al. 2019; cf. Inglehart 1997; Bednar et al. 2010).



For example, one line of evidence from comparative ethnography looks
at cooperative behavior, and reveals variation between groups even in
the kinds of activities, relationships, and contexts that are governed
by norms. Some groups "cooperate only in warfare and fishing,
while others, just downstream, cooperate only in housebuilding and
communal rituals" (Chudek, Zhao, & Henrich 2013: 426). That
behavioral variations like these can persist even in the face of the
same ecological context (i.e., "just downstream") suggests
that they are due to differences in norms and other socially
transmitted elements of culture, rather than responses more directly
evoked by the physical environment (also see N. Henrich & J.
Henrich 2007).



It is a platitude that different individual norms, identified by the
context in which they apply, their scope and content, and the specific
behaviors they prescribe and proscribe, are present in different
cultures. Systematic empirical work has also recently investigated the
prominence of different normative *themes* across cultures.
Familiar examples include the different families of norms that mark
cultures of honor versus cultures of shame, especially those that that
govern violence and its aftermath (Nisbett & Cohen 1996; Uskal et
al. 2019), or the different kinds of norms found in societies that
prize individualistic values versus those dominated by more
collectivist ones, especially norms that delimit the scope of personal
choice (McAuliffe et al. 2003; Nisbett 2004; Ross 2012, Hagger
Rentzelas, & Chatzisarantis 2014; J. Henrich forthcoming, also see
J. Henrich, Heine, & Norenzayan 2010 for discussion of
methodological issues). Other researchers have distinguished still
other themes, for instance identifying the kinds of values and
"purity" norms that predominate in a community governed by
what they call an ethics of divinity, in comparison to those prevalent
in communities that are governed by an ethics of autonomy or an ethics
of community (Shweder et al. 1997; Rozin et al. 1999; this line of
thought has been further developed in the influential Moral
Foundations Theory, Haidt 2012; Graham et al. 2013). Theorists also
use these kinds of empirical findings to help assess claims about norm
psychology, shedding light on those features of individual normative
cognition that are more rigid and universal versus those that are more
culturally malleable, and on how such psychological features might
make various patterns of group-level variation more or less likely
(O'Neill & Machery 2018).



A recent and intriguing contribution along these lines is Gelfand and
colleagues' investigation of patterns in the *tightness*
and *looseness* of different cultures' norms. This work
looks at differences in the general overall "strength" of
norms within and across cultures: how many norms there are, how
tolerant members of a culture tend to be of deviations from
normatively prescribed behavior, and how severely they punish
violations (Gelfand, Nishii, & Raver 2006; Gelfand, Raver, et al.
2011; Gelfand, Harrington, & Jackson 2017). Tighter cultures have
more numerous and exacting standards, with members who are less
tolerant of slight deviancies and prone to impose more severe
sanctions. Cultures whose members are more lenient and accepting of
wiggle room around a norm, and who are less extreme in their
enforcement, fall more towards the loose end of this spectrum. Gelfand
and colleagues explore the manifestations of tightness and looseness
not just at the level of cultures but also across a number of other
levels of description, from the communal and historical down to the
behavioral, cognitive, and neural (Gelfand 2018). A central claim of
this account is that a culture's orientation towards
norms--whether the norm systems of its members tend to be
calibrated more tightly or more loosely--reflects the severity of
the challenges faced in its past and present: 



> 
> 
> [t]he evolution of norm strength is *adaptive* to features of
> ecological environments and, in turn, is afforded by a suite of
> adaptive psychological processes. (Gelfand, Harrington, & Jackson
> 2017: 802, our italics) 
> 
> 
> 



A group whose ecology is characterized by things like frequent natural
disasters, disease, territorial invasion, or resource scarcity is
likely to possess a more comprehensive and exacting system of norms
and to take a stricter stance towards its norms, in part because more
efficiently coordinated social action is required to overcome more
severe threats. Groups faced with less extreme ecological stressors
have less dire need for tightly coordinated social action, and so can
afford to have weaker norms and more tolerance for deviation.


### 2.2 Behavioral Economics



Behavioral economics began by focusing on how real people make actual
economic decisions, and on explaining the type of information
processing that leads them to fall short of ideal economic rationality
(Kahneman 2011). In the last few decades, many behavioral economists
have also begun to investigate cross cultural variation in economic
behavior, and to interpret findings in terms of the different norms
of, e.g., fairness, equity, and cooperation adopted by their
participants (e.g., Lesorogol 2007). Much of this evidence comes from
patterns in how people from different cultures perform in economic
games (J. Henrich, Boyd, et al. 2001, 2005). Such variation, for
example, has been found in ultimatum game experiments, in which two
participants bargain about how to divide a non-trivial sum of
money. The first participant makes a proposal for how to divide the
sum between the two, which is offered as an ultimatum to the
other. The second participant can either accept or reject the
offer. If she accepts, then both participants receive the respective
amounts specified by the proposal; if she rejects it, however, neither
participant receives anything. If they were ideal economic agents,
then the first participant, acting from self-interest, would offer the
lowest possible non-zero amount to the second participant, who would
accept it because something is better than nothing. This result is
quite rare in humans, however (though it is more common, intriguingly,
in chimpanzees; see Jensen, Call, & Tomasello 2007). Actual people
do not just diverge from it, but diverge from it in different
ways. Several experiments found that cultural factors affect how
people tend to play the game, and that variability in norms and
conceptions of fairness can help explain different patterns in the
offers participants make and are willing to accept (Roth et al. 1991;
though see Oosterbeek, Sloof & van de Kuilen 2004 for discussion
of difficulties in interpreting such results). Other experiments use a
wider range of games to gather evidence of similar patterns of
cultural variation in economic behavior (see J. Henrich, Boyd, et al.
2004 for a collection of such work).



Another family of findings that is puzzling from the point of view of
classical economic rationality shows that individuals will routinely
punish others even at a cost to themselves (Fehr & Gachter 2002;
J. Henrich, McElreath, et al. 2006). Evidence suggests that this
propensity to punish is influenced by norms and other cultural factors
as well (Bone, McAuliffe, & Raihani 2016). For example, in public
goods games participants are given a non-trivial sum of money and must
decide if and how much to contribute to a common pool over the course of
several rounds. How much each investment pays off depends on how much
everyone collectively contributes that round, so each
participant's decisions should factor in the behavior of every
other participant. In some versions, participants can also spend their
money to punish others, based on knowledge of the contributions they
have made. Results indicate that some participants are willing to
incur a cost to themselves to sanction low contributors, but also to
punish *high* contributors, a surprising phenomenon called
*anti-social punishment*. Participants from different cultures
exhibit different patterns in their willingness to punish others,
including in their enthusiasm for anti-social punishment (Herrman,
Thoni, and Gachter 2008). Another noteworthy aspect of
punitive behavior revealed by behavioral economic experiments is that
humans are willing to punish even when they are mere bystanders to the
incident that they are responding to. In such cases of *third-party
punishment*, an individual enforces a norm despite the fact that
she is neither the offend*er* who commits the violation and
becomes the target of the punishment, nor the offend*ed* who
was wronged or the victim affected by the transgression (Fehr &
Fischbacher 2004; though see Bone, Silva, & Raihani 2014).



More broadly, the general psychological propensity for punishment
illuminated by this kind of empirical work has been claimed by
researchers to emerge early in humans (Schmidt & Tomasello 2012;
McAuliffe, Jordan, & Richerson 2015). Some have argued that it is
crucial to a host of features of human social life, including the
group-level stabilization of norms (Boyd & Richerson 1992) and the
capacity to sustain cooperation on large scales (Price, Cosmides,
& Tooby 2002; Mathew & Boyd 2011; Mathew, Boyd, & van
Veelen 2013). Others have used such results to support inferences
about the character of normative psychology, including the nature of
normative motivation. For instance, Chudek and Henrich summarize
several neuroeconomic studies (Fehr & Camerer 2007; Tabibnia,
Satpute, & Lieberman 2008; and de Quervain et al. 2004) that
investigate economic behavior using the methods and technology of
neuroscience (i.e., fMRI) by pointing out that 



> 
> 
> both cooperating and punishing in locally normative ways activates the
> brain's rewards or reward anticipation circuits in the same
> manner as does obtaining a direct cash payment. (Chudek & Henrich
> 2011: 224)
> 
> 
> 


### 2.3 Developmental and Comparative Psychology



An impressive range of evidence suggests that humans are natural-born
norm learners. The developmental trajectory of norm-guided cognition
in humans appears to exhibit robust similarities across cultures, with
children beginning to participate in normative behavior around the
same early age (see House et al. 2013 and Tomasello 2019 for context).
Between three and five years of age children exhibit knowledge of
different kinds of normative rules (Turiel 1983; Smetana 1993; Nucci
2001), and at as early as three years of age they are able to perform
competently in deontic reasoning tasks (R. Cummins 1996; Beller 2010).
They also enforce norms, both when they believe the transgressive
behavior was freely chosen (Josephs et al. 2016) but also when they
understand that it was unintentional (Samland et al. 2016) at least in
some circumstances (cf. Chernyak & Sobel 2016; also see Barrett et
al. 2016 and Curtin et al. forthcoming for evidence and discussion of
cross cultural variation in people's sensitivity to the mental
states of norm violators). Moreover, children are alert to how other
people respond to transgressions, showing more positive feelings
towards those who enforce a norm violation than toward those who leave
violations uncorrected (Vaish et al. 2016).



Perhaps most striking is the ease and rapidity with which children
acquire norms. Preschoolers have been found to learn norms quickly
(Rakoczy, Warneken, & Tomasello 2008), even without explicit
instruction (Schmidt, Rakoczy, & Tomasello 2011), although
learning is facilitated when norms are modeled by adults (Rakoczy,
Haman, et al. 2010). Children's enthusiasm for rules--their
"promiscuous normativity" (Schmidt, Butler, et al.
2016)--even appears to outstrip being sensitive to common
norm-governed behavior in their social environment. Evidence suggests
that sometimes a single observation of an action is sufficient for
children to infer the existence of a norm, and that left to their own
devices they will spontaneously create their own norms and teach them
to others (Gockeritz, Schmidt, & Tomasello 2014).



That said, behaviors that are perceived to be normal in a community are
particularly salient to individuals' norm psychology. Children
are also normatively promiscuous in that they appear prone to false
positives in the course of acquisition, seeing behavior as norm-guided
even when it is merely common, and inferring the presence of normative
rules when there are none. One series of studies found that when
participants (children and adults from both the United States and
China) detected or were told that a type of behavior was common among
a group of people, they came to negatively evaluate group members who
behaved in a non-conforming way (Roberts et al. 2018; Roberts, Ho,
& Gelman 2019). Researchers have investigated this feature of norm
acquisition from different angles, and have labeled it with various
names, including the "descriptive-to-prescriptive
tendency" (Roberts, Gelman, & Ho 2017) the "common is
moral heuristic" (Lindstrom et al. 2017), and the
"injunctive inference hypothesis" (Davis, Hennes, &
Raymond 2018, discussing, e.g., Schultz et al. 2007). Since the
evidence suggests that human normative cognition invites an easy
inference from the "is" of a perceived pattern of common
behavior to the "ought" of a norm (Tworek & Cimpian
2016), philosophers may be tempted to think of this as a
"naturalistic fallacy bias".



Another line of research suggests that key to understanding the roots
of human normativity is the fact that human children are
*overimitators*. They are not just spontaneous, intuitive, and
excellent imitators, but they also tend to copy *all* of the
elements in the sequence of a model's behavior, even when they
recognize some of those elements are superfluous to the task at hand
(Lyons, Young, & Keil 2007; Kenward, Karlsson, & Persson 2011;
Keupp, Behne, & Rakoczy 2013; Nielsen, Kapitany, &
Elkins 2014, cf. Heyes 2018: chapter 6). Children attend to the
specific manner in which an action is carried out rather than merely
to the goal it is aimed at, and conform to the full script even if
they see that the goal can be achieved in some more direct way.
Moreover, children monitor others to see if they are doing likewise,
and enforce overimitation on their peers by criticizing those who fail
to perform the entire sequence of steps (Kenward 2012; Rakoczy &
Schmidt 2013). Overimitation can lead to the unnecessary expenditure
of energy on these extraneous behaviors, but the trait may be an
adaptation nevertheless. According to this argument, the costs of what
look like individual "mistakes" are ultimately outweighed
by the communal benefits generated by a population whose individual
capacities for transmitting norms and other cultural variants are more
insistent in this way, erring on the side of too much imitation rather
than too little (J. Henrich 2015: chapter 7). Whatever it was
initially selected for, researchers have suggested that the
psychological machinery responsible for overimitation makes important
contributions to normative cognition. Evidence indicates that this
machinery generates strong (perhaps intrinsic) social motivation aimed
at behavioral conformity with others. When working in conjunction with
a norm system, this source of motivation may also help facilitate
performance of the key task of keeping an individual's behavior
compliant, inducing her to conform not just to behaviors she is
observing but to those norms she has internalized (Hoehl et al. 2019
for overview).



Overimitation is also noteworthy because it may be distinctively
human. For example, although chimpanzees imitate the way conspecifics
instrumentally manipulate their environment to achieve a goal, they
will copy the behavior only selectively, skipping steps which they
recognize as unnecessary (Whiten et al. 2009, also see Clay &
Tennie 2018 for similar results with bonobos). Evidence suggests that
learning in human children is comparatively more attuned to peer
influence in other ways as well. Once chimpanzees and orangutans have
figured out how to solve a problem, they are conservative, sticking to
whatever solution they learn first. Humans, in contrast, will often
switch to a new solution that is demonstrated by peers, sometimes even
switching to *less* effective strategies under peer influence
(Haun, Rekers, & Tomasello 2014).



However, other researchers have recently contested the claim that
overimitation is strictly absent in non-humans (Andrews 2017). This is one front of a much
larger debate over which features of human psychology are unique to
our species, and which are shared with others. Recent work relevant to
norms has focused on whether and to what extent species other than
humans have the capacities to sustain cumulative culture (Dean et al.
2014), with plausible cases being made that the basic psychological
wherewithal is present not just in some great apes but also in
songbirds (Whiten 2019) as well as whales and dolphins (Whitehead
& Rendell 2015). Another area of focus has been on aspects of
moral cognition, where much illuminating work has explored the
continuities between humans and other animals (de Waal 2006; Andrews
& Monso forthcoming). Much of this is relevant to, but does
not directly address, the question of whether a psychological capacity
dedicated to *norms* is distinctively human, or which of its
component mechanisms might be present in rudimentary form in other
animals. Some have suggested that the propensity to punish, and
especially the tendency for third party sanctioning of norm
violations, is not found in other species (Riedl et al. 2012; Prooijen
2018, though see Suchak et al. 2016). Others point to humans'
exceptional ability to cooperate and their resulting ecological
dominance, suggesting it provides indirect evidence for the uniqueness
of our capacities for culturally transmitted norms (J. Henrich 2015;
Boyd 2017). Not all are convinced, arguing that animals like elephants
(Ross 2019) and chimpanzees (von Rohr et al. 2011) exhibit socially
sophisticated behaviors best explained by the presence of
psychological precursors to core components of the human norm system.
Important preliminary progress has been made on this cluster of
questions concerning non-human normativity (Vincent, Ring, &
Andrews 2018; Andrews 2020; Fitzpatrick forthcoming),
but much conceptual and empirical
work remains to be done.


## 3. Norm Cognition and Morality



Norms are relevant to areas of research across philosophy, the
humanities, and the behavioral sciences, and the kinds of
cognitive-evolutionary accounts of norm psychology described here have
the potential to inform and enrich many of them. The most immediate
implications would seem to fall within the domain of moral theory.
However, the relationship of norms and norm psychology to morality and
moral psychology is not straightforward, and is itself a subject of
debate (Machery 2012). The quest to delimit the boundaries of the
moral domain, and to distinguish the genuinely moral from non-moral
norms, has a long history, but has yet to produce a view that is
widely accepted (Stich 2018). For example, some researchers argue that
there are proximate psychological differences that can be used to
distinguish a set of moral rules from others (conventional rules,
etiquette rules, pragmatic rules). According to one prominent account
rooted in developmental psychology, moral rules are marked by the fact
that individuals judge them to hold generally rather than only
locally, and to apply independently of the pronouncement of any
authority figure, and to govern matters concerning harm, welfare,
justice, and rights (Turiel 1983; Nucci 2001). Some have drawn
inspiration from the sentimentalist tradition in moral theory to build
on this account, explaining the features posited as distinctive of
moral rules by appeal to their connection to emotions like anger or
disgust (Nichols 2004; cf. Haidt 2001). Others have contested the
initial characterization of moral norms, marshalling arguments and
evidence that it is not psychologically universal, but is rather
parochial to certain cultures (Kelly et al. 2007; Kelly & Stich
2007, also see Berniunas, Dranseika, & Sousa, 2016;
Berniunas, Silius, & Dranseika, 2020; cf. Kumar 2015; Heath
2017).



Shifting focus from proximate to ultimate considerations seems to add
little clarity. While some theorists hold that our species possesses
an evolved psychological system dedicated specifically to morality
(Joyce 2007; Mameli 2013; Stanford 2018; cf. Kitcher 2011), others
remain skeptical. They argue instead that the evidence better supports
the view that humans have an evolved psychological system dedicated to
norms in general, but there is nothing about the mechanisms that
underlie it, the adaptive pressures that selected for it, or the norms
that it can come to contain that would support a distinction between
moral norms and non-moral norms (Machery & Mallon 2010; Davis
& Kelly 2018; Stich forthcoming). On this view, rather, the human
norm system evolved to be able to deal with, and can still acquire and
internalize, a wide range of norms, including epistemic norms,
linguistic norms, sartorial norms, religious norms, etiquette norms,
and norms that might be classified by a contemporary westerner as
moral. Indeed, the claim has been taken to support a historicist view
of morality itself, according to which the practice of distinguishing
some subset of norms and normative judgments as moral, and thus as
possessing special status or authority, is a culturally parochial and
relatively recent historical invention (Machery 2018).



That said, several debates with broadly moral subject matter have
already begun drawing on empirically inspired accounts of norm
psychology. For example, philosophical discussions of the moral
questions raised by implicit social biases have recently assumed the
shape of venerable and long-standing debates between individualists
and structuralists (Beeghly & Holroyd 2020, also see Brownstein
2015 [2019]). A central issue has been whether behaviors are best
explained and injustices best addressed by focusing attention on
individual agents and their implicit biases and other psychological
characteristics, on the one hand, or on features of the institutions
and social structures that those agents inhabit, on the other
(Haslanger 2015). This has inspired attempts to develop an
interactionist account that can combine the virtues of both approaches
(Madva 2016; Soon 2020).
Several of these have put norms center stage (Ayala-Lopez
2018), and drawn on empirical research on norm psychology to show how
norms serve as a connective tissue that weaves individuals and soft
social structures together (Davidson & Kelly 2020).



Cultural variation in norms and persistent disputes over right and
wrong have been thought to have significant implications for
metaethics as well. The "argument from disagreement" (Loeb
1998) holds that if dispute over the permissibility of some activity
or practice persists even after reasoning errors and non-moral factual
disagreements have been resolved, such intractable disagreement would
militate against moral realism (Mackie 1977). Empirically establishing
the existence of persistent disagreement is difficult (Doris &
Plakias 2008), but the character of the norm system and its influence
on judgment may speak to whether or not it is likely. Consider two
individuals from different cultures, who have internalized divergent
families of norms (individualistic and collectivist, honor based and
shame based, divinity and autonomy, tight and loose, etc.) Such
individuals are likely to disagree about the permissibility of a range
of activities and practices, such as what counts as a fair division of
resources, or whether people should get to choose who they marry, or
what is and is not an appropriate way to respond to an insult. This
disagreement may very well endure even in the face of agreement about the
non-moral facts of the matter, and even when neither side of the
dispute is being partial or making any reasoning errors. Such
persistent disagreement may be explainable by appeal to differences in
the individual's respective norm systems, and to the different
norms each has internalized from his or her culture (Machery et al.
2005). Empirical details of the operational principles of normative
cognition--especially knowing whether and the extent to which it
is informationally encapsulated, cognitively impenetrable, or
otherwise recalcitrant and insensitive to other psychological
processes--can help assess the plausibility of this argument.



A final set of debates to which the details of norm psychology are
becoming increasingly relevant are those concerning the nature and
explanation of moral progress. Recent progress is understood to have
largely come in the form of expansions of the moral circle, the spread
of inclusive norms, and the demoralization of invalid ones (Singer 1981; Buchanan
& Powell 2018; cf. Sauer 2019.) Much attention has focused on
understanding changes in the distribution of norms that occur as the
result of *reasoning* about norms (Campbell & Kumar 2012), but
important steps towards moral progress may also occur as the result of
myopic, though not fully blind, processes of cultural evolution (cf.
Kling 2016; Brownstein & Kelly 2019). A more detailed empirical
understanding of the relationship of internalized norms to
rationalization, critical reasoning, and explicit argumentation
(Summers 2017; Mercier & Sperber 2017), along with a clearer view
of the other psychological and social factors that influence norms and the
dynamics of their transmission, will help further illuminate these
important philosophical debates.