Humans have well-established capabilities for adapting their preferences in ways that improve their subjective happiness. I argue that there is an intriguing case for conceiving moral motivations—that is, the robust psychological structures that reliably undergird everyday moral behaviour—as adapted preferences. The typical situation facing people provides self-interested material rewards for behaving morally in most but not all cases. In response to this situation, I argue that it is rational (that is, subjective-happiness-maximising) for people to adapt their preferences in ways that elevate their subjective payoffs for consistently moral behaviour. In this way, people can be incentivised by their self-interest to strategically supersede their self-interestedness. Drawing on the burgeoning scholarship on adaptive preferences, I suggest this can be achieved through changes in experiences, desires, cognitions, frames, and identities. While the thin content of moral obligation is broadly fixed by the game theoretic parameters of typical human interactions, the thick, rich, adapted preferences that motivate people to conform to this moral content are dazzlingly diverse, as different cultures and individuals employ different resources to achieve the desired adaptation. In a nutshell, we discover moral duties, but must construct moral motives.
