In the modern world, most of a person’s material possessions are items that no individual could possibly make by herself. Instead they were produced with the learned and specialized expertise of others. In Chapter 17, Robert Boyd and colleagues argue that learning from others (and not intelligence alone) is the key to human success, the characteristic that has made us so adaptable. Initially in human history, most adaptations involved direct climatic protection, food acquisition, and food storage. Thus, the sharing and acquiring of information from others is a particular kind of intelligence. Boyd and his coauthors argue that cultural learners have an advantage because they can grasp the best from the past even if they innovate personally only occasionally. Tools and customs certainly make life for humans easier or possible.
The study of cooperation and conflict has come a very long way from the time, almost 50 years ago, when Hamilton (1964a,b) first pondered how to explain the evolution of worker behavior in social insects with a strange genetic system. Such analyses have spread out taxonomically, extending even to microbes. They have deepened mechanistically as we probe the molecular and genetic basis of cooperative phenomena. The findings are also beginning to show practical applications, as in medicine, and they have proven essential for understanding the structure of life, from cells to multicellular organisms to societies. Not least, study of the complex mix of cooperation and conflict helps us to understand what makes the human animal both ordinary and remarkable.