Behave: The Biology of Humans at Our Best and Worst

Sapolsky opens Behave with recapitulating a fantasy he has had “since I was a kid” (2) of personally capturing Hitler during World War II and committing sadistic acts of violence against him as punishment for his atrocities. This is a startlingly dark and also comically self-effacing passage to begin a popular science book. However, in acknowledging that many would agree with leaving Hitler “paralyzed, but with sensation” (1) before torturing him, this passage illustrates “a central point of this book—we don’t hate violence. We hate and fear the wrong kind of violence, violence in the wrong context” (3). This book explores the biology of “right” and “wrong” human acts including aggression, violence, altruism, and self-sacrifice.

Sapolsky then moves to a second section, “The Approach in this Book” (4), in which the author outlines that this book will be purposefully cross-disciplinary, including endocrinological, neurobiological, and evolutionary explanations of human behavior. This is intended to create a holistic and readable approach to the complex topic that avoids common scientific quagmires of reducing behavior’s complexity to the findings possible in a single field.

In the third section of the Introduction, “Our Lives as Animals and our Human Versatility at Being Aggressive” (10), Sapolsky makes the point that most of human behavior has clear correlates in the animal kingdom. When we’re scared, “we secrete the same hormone as would some subordinate fish getting hassled by a bully. The biology of pleasure involves the same brain chemicals in us as in a capybara” (11). Therefore, studying the science of behavior means studying the science of animal behavior (ethology), and study of animal behavior in both natural and laboratory settings will be a major source of information for this book.

The correlation between human and animal behavioral biology also extends to the biology of aggression, though with important differences: “We use the same muscles as does a male chimp attacking a sexual competitor, but we use them to harm someone because of their ideology” (11). In other words, while understanding human behavior means understanding its evolved components, it also means understanding its uniquely human aspects, such as morality, belief, complex thought, planned violence, etc. Studying human behavior at its best and worst means looking at both what connects and what distinguishes us from all other animals.