In the 1980s, Ruse wrote a series of important papers that revived evolutionary ethics. The debate on the implications of evolved moral intuitions for ethics remains very active up to today (see e.g., this conference that I'll be attending in a couple of hours, at least if the British railway system isn't disrupted by half an inch of snow!). Contemporary evolutionary ethics can build on a wealth of research, for instance, in the cognitive neuroscience of morality, developmental psychology, and the study of altruism in animals. But the metaethics of the folk remains a relatively understudied area. Are people intuitive moral realists? If so, what is the connection between metaethics and behavior?
Ruse hypothesized that humans are intuitive moral realists, and that this metaethical intuition has an evolved function: "human beings function better if they are deceived by their genes into thinking that there is a disinterested objective morality binding upon them, which all should obey" (Ruse & Wilson, 1986, 179). Ruse thought that if everyone thought that morality was subjective, that it was merely a matter of taste or convention, our social systems would collapse. Intuitive moral realism was thus a key component in human altruistic behavior, held together by moral beliefs, which in turn were cemented by intuitive moral realism. As Ruse wrote later on: "Substantive morality stays in place as an effective illusion because we think that it is no illusion but the real thing" (Ruse, 2010, 310).
When Ruse first formulated this hypothesis, it was by no means clear that humans were intuitive moral realists. Also, it was not clear to what extent an intuitive moral realism, if anything, helped us to act more morally. In the meantime, there is some empirical work on this, which I'll discuss briefly below the fold.