Nichols argues convincingly that what is wrong with psychopaths is not their reasoning but their
emotions. I mentioned earlier in this chapter the theory that psychopathy, whose symptoms include
antisocial behavior, lack of guilt, and poverty of emotions, is the result of impairments to emotional
learning that derive from disrupted functioning of the amygdala.
According to Nichols, an adequate account of ethical thinking must explain how emotion plays a
role in linking moral judgment to motivation, while also allowing a place for reason in moral
judgment. His explanation of ethical norms is cultural and historical: “Norms are more likely to be
preserved in the culture if the norms resonate with our affective systems by prohibiting actions that
are likely to elicit negative affect.” Norms that prohibit harm to others are virtually ubiquitous across
cultures because of this “affective resonance.” The adoption of norms enables us to reason about what
is right and wrong, but these norms have an emotional underpinning that intrinsically provides a
connection between morality and action: people are moral because of their emotional commitment to
normative rules.