Humans are not isolated individual minds inside chemical/mechanical bodies, but social animals whose interaction with each other define who we are as a species. Intuitively we understand the limitations of the mechanical model, which separates our bodies from us. Nor are we so separate from other people. We are born into families, and we live in communities. Our earliest ideas of a happy and healthy life are social. They come from what little we know, and some of what we fantasize about when we think of prehistoric hunter-gatherers. Much of the literature claims that they lived in small bands with strong social relationships but little formal organization. They made few distinctions between the roles of men and women, and decisions were made by consensus. These early humans are almost always said to have lived well and to have been relatively healthy. They spent no more than two hours a day gathering food and had leisure for the rest of the day; playing with their children, socializing with other tribe members, and resting. They were not affected by infectious diseases, which require a larger population in which to spread. 140The women had much less pain from childbirth because stooping to forage strengthened their birthing muscles. Many descriptions of the earliest humans are positive, even idyllic, like life in the Garden of Eden. Though some of this is most likely fantasy, it can serve as a somewhat sentimental account of a desirable social/relational healthy life that disappeared with the coming of agriculture.