Since the emergence of Western philosophy and science among the classical Greeks, debates have raged over the relative significance of biology and culture on an individual’s behavior. Today, recent advances in genetics and biological science have pushed most scholars past the tired nature vs. nurture debate to examine the ways in which the natural and the social interact to influence human behavior. In What’s Normal?, Allan Horwitz brings a fresh approach to this emerging perspective. Rather than try to solve these issues universally, Horwitz demonstrates that both social and biological mechanisms have varying degrees of influence in different situations. Through case studies of human universals such as incest aversion, fear, appetite, grief, and sex, Horwitz first discusses the extreme instances where biology determines behavior, where culture dominates, and where culture overrides basic biological instincts. He then details the variety of ways in which genes and environments interact; for instance, the primal drive to eat and store calories when food supplies were scarce creates serious problems in a society where food is abundant and obesity stigmatized. Now that it’s often easier to change our biology rather than our culture, an understanding of which behaviors and traits are simply normal or abnormal, and which are pathological or necessitate treatment is more important than ever. Wide-ranging and accessible, What’s Normal? provides a crucial guide to the biological and social bases of human behavior at the heart of these matters.