Robert Kurzban, Ph.D., is currently an assistant professor at the University of Pennsylvania in the department of psychology. He received his Ph.D. at the Univeristy of California Santa Barbara, and received postdoctoral training at Caltech, UCLA, and the University of Arizona. His research focuses on evolved cognitive adaptations for navigating the social world in domains such as mate choice, friendship, morality, and cooperation. Visit him online at http://www.psych.upenn.edu/PLEEP.