Oliver Scott Curry, the paper’s head author, is an anthropologist who studies the evolutionary basis for moral sentiments and values. In a post at the online magazine Behavioral Scientist, Curry argued that previous attempts to use evolutionary psychology to understand how humans came to evolve a sense of morality have fallen short. In particular, Curry took aim at Moral Foundations Theory, the well-known framework for studying moral psychology developed by Jonathan Haidt (now a professor at New York University). Moral Foundations Theory posits that moral intuitions come in five different “flavors,” or basic types: care, fairness, in-group loyalty, authority, and purity. Many studies have found that self-described conservatives tend to value all five of these foundations equally, while self-identified liberals value care and fairness (the “individualizing” foundations more highly than the other three (the “binding” or “groupish” foundations).