The Secret of Our Success: How Culture Is Driving Human Evolution, Domesticating Our Species, and Making Us Smarter

The Secret of Our Success explores the importance of cultural evolution in the success of homo sapiens. The book also explores the ways in which cultural evolution can synergisticly work with genetic evolution.

The social aspect of culture can be compared somewhat to moving work to the cloud. On one side, you can get more and more powerful computers. However, you can also combine many smaller computers together to achieve similar results. Combining the smaller computers also allows for more resiliency and rapid expansion. The culture can provide similar benefits. We don't need to re-learn what foods are safe and how to prepare them. Our culture is built on previous discoveries. Today we have tools and technologies built on top of many levels of previous ones.

This does have some challenges. As isolated societies grow smaller, they can lose cultural knowledge. There are also challenges when certain knowledgeable people are lost. (There is an example of a society that lost its kyak builders.) 

Skin color is an interesting example of cultural and genetic evolution working in tandem. Darker skin is beneficial in warmer, sunnier climates. In more northerly climates, paler skin allows for more vitamin D formation and is beneficial for farming societies. However, Inuit societies are able to obtain the needed vitamins from the animals they consume in the arctic. Thus, the lighter skin is not as beneficial. We see cultural and genetic needs working in tandem.

Norms and goals are important. Societies have different languages, taboos and ways of doing things. They are often adopted based on observance of "models".  Often these norms are based on some need that is now no longer understood. There are often seemingly "odd" behaviors that were built on a social requirement. (For example, food may be prepared in certain ways to provide needed nutrition.) There can also be cultural norms that were merely adopted based on models without any useful requirements. Different languages result in different types of communications. Some also have a sound structure that is optimized for the particular environment.

Cultural evolution became an integral part of human evolution. We have trouble surviving individually without our culture. Even eating is dependent on cultural learning. Our digestive system is not optimized for eating available raw foods. We need cooking and other processing for most of our eating. Genetic evolution has worked in tandem with the cultural evolution to optimize for the beneficial genes and let redundant ones to fade out. We don't need to rely on one individual brain, but can take knowledge from society past and present.