Biology and culture evolve together.

For example, cattle-herding is a cultural adaptation, and lactose tolerance is a biological adaptation. Those adaptations evolved together and fit together. Each selects for the other. The two adaptations together are more useful than either is separately. You can’t just take a bunch of lactose intolerant people and drop them into a cattle-herding culture. They will get sick, because their biology does not fit the culture. The linked adaptations of cattle-herding and lactose tolerance emerged in two different parts of the world, Europe and Africa, thousands of years ago, and have spread widely since.

The coevolution of biology and culture makes them fit together. They cohere. They are codependent.

Society and culture are also codependent. To live together in a society, people need a common culture, which includes language and concepts that are necessary for social organization. People develop a common culture by living together in the same place and interacting. Social interaction requires a common culture and creates a common culture. Society depends on culture, and culture depends on society.

Money is a good example of the codependence of culture and society. Money has value because people believe it has value. That belief is part of culture. Everyone shares that belief. Why do people believe that money has value? Because they can use it to purchase things. The use of money is part of society. Buying things, working for wages, and paying taxes are social interactions. The use of money in those social interactions creates the belief that money is valuable. The belief that money is valuable makes the use of money possible. The cultural belief and the social use emerged together. Neither can exist without the other.

For a society to exist, its laws and institutions must be viewed as good (or mostly good) by the people. People tend to view the existing social order as good, because they are familiar with it. For the most part, morality consists of cultural norms of behavior. Those cultural norms emerge within a social context, and are shaped by that social context. Society reinforces moral norms with rewards and punishments. Society imposes morality on its members, but society also depends on the moral approval of its members. Cultural norms depend on social power. Social power depends on cultural norms.

Society and biology are also codependent.

We have an innate capacity to develop social relationships. We instinctively seek acceptance, approval and status from others. We feel positive or negative empathy (like or dislike) toward others based on past interactions. Social emotions are the biological basis of society. They cause us to organize into cooperative groups. Social emotions are also an adaptation to living in a group. The adaptation creates the environment that it is adapted to.

Different types of society create different selective pressures. Those selective pressures then shape the genome of the society. If a society selects for traits that make individuals better members of society, then the society will become stronger over time. If it does not, then it will become weaker.

Biology, culture and society are different types of order. Each type of order is created by selection acting on variation. Each is selected for its ability to function effectively in an environment that includes the other two. Biology, culture and society fit together into a system that functions as a whole.

I call this relationship “adaptive coherence”. Codependency and coevolution create coherence.