Bipedalism, the defining characteristic of humanity, is explored as the evolutionary catalyst for our species' most significant traits. Jeremy DeSilva, drawing on seven million years of human evolution, argues that the seemingly inefficient act of walking upright unlocked crucial human attributes. The book examines the instinctual drive for bipedalism from infancy, discusses the gendered differences in gait, and details the physical drawbacks such as hernias and back pain. Furthermore, it posits that upright walking laid the groundwork for our capacity for compassion, empathy, and altruism, ultimately enabling us to become the planet's dominant species.

This book is recognized for its comprehensive exploration of human evolution, specifically focusing on the significance of bipedalism. It is lauded for connecting this fundamental physical trait to a wide array of uniquely human characteristics, from technological innovation to complex social behaviors and emotional capacities. The author's synthesis of evolutionary biology, anthropology, and behavioral science provides a compelling narrative on how walking upright shaped our species.