A unique trait of the human species is that our personalities, lifestyles, and worldviews are shaped by an accident of birth--namely, the culture into which we are born. It is our cultures and not our genes that determine which foods we eat, which languages we speak, which people we love and marry, and which people we kill in war. But how did our species develop a mind that is hardwired for culture--and why?

Evolutionary biologist Mark Pagel tracks this intriguing question through the last 80,000 years of human evolution, revealing how an innate propensity to contribute and conform...