The Hadza tribe in Tanzania do not engage in warfare. They've never lived densely enough to be seriously threatened by an infectious outbreak. They have no known history of famine; rather, there is evidence of people from a farming group coming to live with them during a time of crop failure. The Hadza diet remains even today more stable and varied than that of most of the world's citizens. They enjoy an extraordinary amount of leisure time. Anthropologists have estimated that they "work" -- actively pursue food -- four to six hours a day. And over all these thousands of years, they've left hardly more than a footprint on the land. The Hadza recognize no official leaders. None has more wealth; or, rather, they all have no wealth. There are few social obligations -- no birthdays, no religious holidays, no anniversaries. National Geographic asks, "What do they know that we've forgotten?"
