Nature Vs. Nurture & Cultural Evolution

Language is culture. Food is culture. Customs are culture.

They are all taught. They are all shaped and communicated across generations through group orientation and primary socialization.

In the book, Not By Genes Alone: How Culture Transformed Human Evolution, authors Peter J. Richerson and Robert Boyd explain that some scientists argue that culture and human behavior cannot be tied to evolutionary theory and biology, quoting the concept of nature versus nurture.

Culture is something created via nurture, while biology is formed by nature.

An individual’s concept of time, her values and customs, her language – all of this is formed by the environment in which she grows up.

It is nurtured.

An individual’s eye color, his height, any genetic disease he may have – all of this is formed by genes.

It is the result of nature. 

Considering this, many argue that evolutionary theory does not come into play in regards to learned behaviors that are shaped by the environment.

As we’ve discussed in many blog posts, cultural behaviors – and most other human behavior – is learned; therefore, the argument is that biology has little to do with creating it.

But Richerson and Boyd suggest that this is not the case, due to the symbiotic nature of genes and their environment.

Genes & the Environment Interact

Genes are not blueprints specifying an organism’s final draft.

Instead, the genetic information stored in an organism interacts with the environment around it while the organism is developing.

As Richerson and Boyd describe it:

“Genes are like a recipe, but one in which the ingredients, cooking temperature, and so on are set by the environment.”

And like any recipe, the traits of the organism will vary based on the differences in the environment.

Some traits are more affected by environment than others.

For instance, most humans develop two ears, despite the environment they’ve grown in, but depending on their nutritional environment during youth, they can develop different growth and health outcomes into adulthood.

Environmental differences can also cause differing behaviors in organisms that are genetically the same.

In such circumstances, the environment is the direct cause of different traits and behaviors.

And because culture is both a part of the environment and a reaction to it, while genes are the evolutionary response to past environments, neither can be removed from the equation.

They are symbiotic.

We’ll take a closer look at the degree to which genes and culture influence human behavior next week.

Population Thinking: How Darwin’s Theory of Evolution Contributes to Cultural Theory

Charles Darwin is best known for his theories of evolution and natural selection.

But biologist Ernst Mayr asserts that Darwin’s concept of “population thinking” is his most important contribution to biology.

In the book, How Culture Transformed Human Evolution, authors Peter J. Richerson and Robert Boyd delve into why this is the case.

This is what they’ve found.

The Theory of Evolution Evolves Our Thinking

Prior to Darwin’s theories on evolution, species were thought to be static and unchanging.

But what Darwin found was that a fluctuating pool of inherited information was passed on across generations over time, and this information was affected by the daily events of the species’ lives, which were also changing.

The persistence of the daily events and the spread of their prevalence would produce inherent properties and traits within a species.

In line with natural selection, those traits that allowed the “survival of the fittest” were passed on to their offspring.

Not only traits, but behaviors that benefited survival – a process Darwin called “the inherited effects of use and disuse.”

In this way, the core of the evolutionary theory is grounded in population thinking, which is the crux of cultural theory.

Cultural Evolution

Culture is an acquired state of behavior, produced via social learning.

Skills, values, norms, beliefs, attitudes, customs, moral systems – these are all acquired and comprise group culture.

And they all evolve via population thinking.

Like the theory of evolution, this theory of cultural evolution delves into why some attitudes and behaviors carry on in a group and others don’t.

As with evolution, the daily lives of people in a society contribute to the process of cultural change.

For instance, a moral value might, at one point in time, appear more appealing in relation to that era’s daily life or current events, thereby spreading and persisting from person to person in a society and generation to generation in a culture.

Similarly, beliefs and behaviors that are more easily imitable and allow survival will spread, while those that might result in group criticism or early death will vanish.

Over time, the persistence of certain beliefs, skills, attitudes, etc., create observable patterns that serve as the genes of culture.

But culture can adapt in a way that genes cannot.

Over the next few weeks, we’ll talk about how population thinking is enmeshed in culture.