One semester before his marriage, Maslow had enrolled at the University of Wisconsin, from which he received a BA degree in philosophy. In addition, he was quite interested in John B. Watson's behaviorism, and this interest prompted him to take enough psychology courses to meet prerequisites for a PhD in psychology. As a graduate student, he worked closely with Harry Harlow, who was just beginning his research with monkeys. Maslow's dissertation research on dominance and sexual behavior of monkeys suggested that social dominance was a more powerful motive than sex, at least among primates (Blum, 2002).