recently that fish can construct a logical linear hierarchy from paired observations to perform transitive inference just as do primates, thereby identifying cognitive skills required for social systems across vertebrates. Using the CRISPR technique, his group has shown that a single gene controls reproduction in the cichlid fish. He has published several review articles describing the search for the social brain. among his 220 papers and book chapters. References American neuroscientists Stanford University faculty University of Pennsylvania alumni Swarthmore College alumni Living people Year of birth missing (living people)