up of three parts: reflexive consciousness, or the person's awareness of their environment and of himself as an individual; interpersonal being, which seeks to mold the self into one that will be accepted by others; and executive function. They stated, "[T]he self can free its actions from being determined by particular influences, especially those of which it is aware". The three prevalent theories of willpower describe it as a limited supply of energy, as a cognitive process, and as a skill that is developed over time. Research has largely supported that willpower works like a "moral muscle" with a limited supply of strength that may be depleted (a process referred to as Ego depletion), conserved, or replenished, and that a single act requiring much self-control can significantly deplete the "supply" of willpower. While exertion reduces the ability to engage in further acts of willpower in the short term, such exertions actually improve a person's ability to exert willpower for extended periods in the long run. Additional research has been conducted that may cast doubt on the idea of ego-depletion. Moral intuitions In 2001, Jonathan Haidt introduced his social intuitionist model which claimed that with few exceptions, moral judgments are made based upon socially derived intuitions. Moral intuitions happen immediately, automatically, and unconsciously, with reasoning largely serving to generate post-hoc rationalizations to justify one's instinctual reactions. He provides four arguments to doubt causal importance of reason. Firstly, Haidt argues that since there is a dual process system in the brain when making automatic evaluations or assessments, this same process must be applicable to moral judgement as well. The second argument, based on research on motivated reasoning, claims that people behave like "intuitive lawyers", searching primarily for evidence that will serve motives for social relatedness and attitudinal coherence. Thirdly, Haidt found that people have post hoc reasoning when faced with a moral situation, this a posteriori (after the fact) explanation gives the illusion of objective moral judgement but in reality is subjective to one's gut feeling. Lastly, research has shown that moral emotion has a stronger link to moral action than moral reasoning, citing Damasio's research on the somatic marker hypothesis and Batson's empathy-altruism hypothesis. Following the publication of a landmark fMRI study in 2001, Joshua Greene separately proposed his dual process theory of moral judgment, according to which intuitive/emotional and deliberative processes respectively give rise to characteristically deontological and consequentialist moral