Summary of Behave: The Biology of Humans at Our Best and Worst

What makes Behave so compelling is Sapolsky’s unique storytelling framework. He begins by examining what happens in the brain in the exact moment a behavior occurs, then steadily widens the lens to consider the events leading up to it. He starts with the neurobiology of a single second, then moves outward to the sensory stimuli and hormonal changes of hours and days before. From there, he explores how brain development, adolescence, childhood, and even prenatal experiences shape behavior, before reaching further back into genetics, culture, ecology, and ultimately, the evolutionary forces millions of years in the making.

The result is a dazzling tour of science that synthesizes insights across neurobiology, psychology, endocrinology, genetics, anthropology, and evolutionary biology. Behave doesn’t just explain human behavior—it also wrestles with some of the most difficult questions of our time, including the roots of tribalism, xenophobia, hierarchy, morality, and even war and peace.

Wise, humane, and often unexpectedly funny, Behave is both a scientific masterpiece and a deeply humanizing book. Sapolsky provides not only a nuanced perspective on the complexity of human action but also a powerful reminder of our shared humanity, making Behave one of the most ambitious and rewarding works ever written on why we are the way we are.