Roy Baumeister

American social psychologist whose research on ego depletion (self-control as a depleting resource), free will, and gender differences has been highly influential — and whose Is There Anything Good About Men? makes an empirically grounded evolutionary case for understanding male social behavior.

Developed the ego depletion framework — that self-control draws on a limited resource that becomes depleted with use — which, though its replication record is contested, became one of the most influential concepts in popular psychology, and Willpower brought this research to mainstream audiences.