In chapter 7, Wilson examined how culture and genes interact. He began by saying that the natural sciences have an explanatory network that butts up to culture. He noted that the scientific and cultural domains are very exclusive, but that in the spirit of attaining consilience, it is time to bridge the gap. Instead of seeing either domain as a territory to be defended, each area should be attempting to warrant and explain the others.
Wilson began his exploration of culture and genes by noting that amost all human behaviors are transmitted by culture, and therefore biology has an important effect on the origins of culture and its transmission. He described the gene-culture coevolution, which is the theory that as humans evolved, culture evolved in a parallel manner. To sum up Wilson's point, one could say that culture is created by the human mind. The human mind is a product of the human brain. The human brain is a product of biological evolution. Thus, biological evolution and culture are linked together.
Wilson next turned his attention to trying to determine what exactly culture is. The anthropological definition is that culture is a discrete society's way of being, the religioin, myths, social rules, the way knowledge is transmitted, etc. Culture as we know it is only possible because of our use of language. If there were any way to trace the evolution of language, we might be able to trace culture as well, but unfortunately language left no fossil record. According to Wilson, the next best way to understand culture is to reduce it to its smallest units in order to rebuild it. Wilson described the smallest unit of culture as a meme, that is, a node in semantic memory. These memes are arranged hierarchically to create the semantic memories which are then translated into culture.
To further explain how genes and culture interact, Wilson explained three ideas about genes and culture. The first is the hereditary basis of human nature. This is most easily seen in the universals of human culture which have been found. For instance, every single culture has been found to have food taboos, sports, marriage, and religion. Wilson was careful to point out that this does not mean that human beings have a specific gene for marriage or the domestication of animals. Wilson thinks instead that humans have genes which make humans more likely to learn certain behaviors.
Wilson called this phenomenon epigenetic rules of social behavior, and it was the second idea about genes and culture. There are primary epigenetic rules that govern basic sensory perception and secondary epegenetic rules that govern processes such as face recognition. He noted that most of our primary epigenetic rules help us interpret audio-visual cues.
The third idea was the genetic basis of those epigenetic rules. While it is difficult to pin these rules to precise genes, Wilson noted that it can in fact be done and it should be the focus of biologists in the future. Wilson said that genes create the epigenetic rules, which help us to acquire culture. The culture that arises then selects specific genes which then create selective epigenetic rules, thus tweaking the culutre evolution.