Moral psychology investigates the psychological processes underlying moral judgment, motivation, and development. It bridges philosophy and empirical psychology, asking: what are moral intuitions and how reliable are they? How do emotions like empathy and disgust shape moral responses? Are moral character traits stable across contexts (situationism vs. virtue)? Jonathan Haidt's social intuitionist model argues that moral judgments are primarily emotional and automatic, with reasoning post-hoc rationalization. This challenges the rationalist tradition (Kohlberg's stages) and raises normative questions about when we should trust intuitions versus revise them. Joshua Greene's dual-process theory uses trolley-problem data to argue that deontological intuitions stem from emotional responses while consequentialist reasoning is more deliberate.
Read Haidt's 'The Emotional Dog and its Rational Tail' (Psychological Review, 2001) and Greene's papers on the trolley problem. Then evaluate: do empirical findings about how we reason debunk our moral judgments, or do they merely explain their causal history without undermining their epistemic status?
You already know from virtue ethics that moral character involves stable dispositions—the virtuous person acts well because of who they are, not just because they calculated the right answer. Moral psychology takes a step back from normative ethics and asks a more empirical question: how do human beings actually form moral judgments? The answer turns out to be far messier than the rationalist tradition assumed, and the implications for ethics are genuinely unsettling.
Jonathan Haidt's social intuitionist model is the starting point. The key claim is that moral judgments are typically fast, automatic, and emotionally driven—more like perceiving than reasoning. When you see someone kick a dog for fun, you don't compute consequences and consult principles; you feel immediate revulsion and only later, if pressed, reach for reasons. Haidt calls the reasons we produce afterward post-hoc rationalization: the judgment was already made; the argument is constructed to justify it. This inverts the rationalist picture (Kohlberg's stages) where careful moral reasoning produces the judgment. Think of your cognitive biases work: we already know that humans are poor at recognizing when reasoning is motivated rather than objective. Haidt is applying that insight directly to ethics.
Joshua Greene extended this with dual-process theory, using trolley-problem data. The famous footbridge case—where you must push a large stranger off a bridge to stop a trolley from killing five—generates strong deontological intuitions in most people (you shouldn't push), even though the utilitarian math is identical to the switch-lever case (where most people say pull the lever). Greene argues the difference is emotional proximity: physical contact triggers an alarm system in the brain, generating a strong "don't do it" response. More deliberate, System 2 reasoning tends to favor consequentialist conclusions. So deontological and consequentialist intuitions may map onto different cognitive systems, not just different principles.
The deepest question moral psychology raises is what philosophers call the debunking problem: if a moral belief has a causal explanation in emotional mechanisms—mechanisms that evolved for reasons having nothing to do with moral truth—does that undermine the belief's justification? Not automatically. The causal history of a belief doesn't automatically determine its epistemic status; true beliefs can have non-truth-tracking causes, and emotions can be reliable guides in domains they're calibrated to. But the debunking worry is sharpest when intuitions conflict with each other or with careful argument. If your disgust response tells you something is wrong but no principled reason emerges, the fact that disgust is a blunt evolutionary instrument gives you grounds to revise. Moral psychology supplies tools for deciding when to trust and when to override our moral intuitions—a decision that ordinary ethics can't make without this empirical backdrop.
Topics in reflective domains aren't scored by quiz answers. Read, reflect, and mark when you've thought it through.