The "three natures" of Homo sapiens - - -

Our first nature consists of innate feelings, reactions, and preferences that evolved over the course of hundreds of thousands of years and proved their effectiveness in the daily lives of small groups of hunter-gatherers.

The products of our first nature include myriad propensities, such as love between parent and child, a sense of fairness and outrage at injustice and inequality, a loathing for incest and infanticide, a fear of strangers and concern for reputation, a feeling of obligation after receiving gifts or assistance, jealousy, revulsion, and—not to forget our sense of religion—the tendency to see supernatural actors at work everywhere. In a nutshell, our first nature makes itself known in the form of intuitions and gut feelings.

Our second nature consists of habits, conventions,ways of thinking. These cultural products cannot be inherited; once they have proven themselves, they can only be handed down and learned. Adults actively ensure that children internalize these behaviors during early childhood—to such a great extent that they come to make up our second nature.
If we consider our first nature our “natural nature,” this second nature is our “cultural nature.”

It is important to keep in mind that our innate feelings still underlie our second nature, which may even co-opt them for its own purposes. This is why people react with revulsion (first nature) to the eating habits (second nature) of other cultures.

The realm of second nature includes traditions and customs, religion as a cultural product (the kind that is practiced in church, for example), and most of the things that Norbert Elias describes in The Civilizing Process.

Our third nature reflects our rational side. Third nature consists of the maxims, practices, and institutions that we follow consciously—due to a targeted analysis of a given situation, for example. Third-nature products are also internalized to a certain degree, but this usually occurs at a later phase of development—at school or in other institutions.

In the prehistoric environment in which human evolution took place, we used our first nature’s feelings and intuitions as a compass to navigate daily life. Our second nature supplied us with special habits, techniques, moral prescriptions, and social practices such as rituals, which varied from group to group. Our third nature only came into play in emergency situations when we faced new challenges and tried-and-true mechanisms no longer performed as expected.

The result is a latent discontent with civilization, a recurrent feeling of living in an upside-down world. Our second and third natures are cultural products. They have helped us survive, but they don’t necessarily make us happy.

(Adapted from the book "The Good Book of Human Nature: An Evolutionary Reading of the Bible" by Carel van Schaik and Kai Michel)