Human beings are diverse and live in diverse ways. Should we accept that we are diverse by nature, having followed separate evolutionary paths? Or should we suppose that we share our biological inheritance, but develop differently according to environment and culture? Over recent years scientific research has reshaped this familiar “nature-nurture” debate, which remains central to our understanding of human nature and morality.
For much of the 20th century social scientists held that human life is a single biological phenomenon, which flows through the channels made by culture, so as to acquire separate and often mutually inaccessible forms. Each society passes on the culture that defines it, much as it passes on its language. And the most important aspects of culture—religion, rites of passage and law—both unify the people who adhere to them and divide those people from everyone else. Such was implied by what John Tooby and Leda Cosmides called the “standard social science model,” made fundamental to anthropology by Franz Boas and to sociology by Émile Durkheim.
More recently evolutionary psychologists have begun to question that approach. Although you can explain the culture of a tribe as an inherited possession, they suggested, this does not explain how culture came to be in the first place. What is it that endows culture with its stability and function? In response to that question the opinion began to grow that culture does not provide the ultimate explanation of any significant human trait, not even the trait of cultural diversity. It is not simply that there are extraordinary constants among cultures: gender roles, incest taboos, festivals, warfare, religious beliefs, moral scruples, aesthetic interests. Culture is also a part of human nature: it is our way of being. We do not live in herds or packs; our hierarchies are not based merely on strength or sexual dominance. We relate to one another through language, morality and law; we sing, dance and worship together, and spend as much time in festivals and storytelling as in seeking our food. Our hierarchies involve offices, responsibilities, gift-giving and ceremonial recognition. Our meals are shared, and food for us is not merely nourishment but an occasion for hospitality, affection and dressing up. All these things are comprehended in the idea of culture—and culture, so understood, is observed in all and only human communities. Why is this?