How we inherit male and female behavior: a new idea about the environment and genes

Men and women

A notorious Google note , written by engineer James Damore, has caused many years of controversy about differences between women and men.

Everyone, including Damore , recognizes the role of our social environment in shaping gender differences. Ideas about which jobs are “suitable” for women, the pressure exerted on men playing “courageous” roles — these sensations, expectations and opportunities affect our gender role.

But it is usually considered that biological differences between the sexes create differences in behavior that even equal conditions cannot overcome.
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In his note, Damore used scientific ideas, suggesting that the usual differences in interests between men and women (“things” and “people”) and preferences ( status and competition versus family and cooperation) are partially explained by evolutionary, biological differences.

If you adhere to this widespread view, even the liberal environment of Silicon Valley cannot overcome such a deep-rooted opinion.

But what if thousands of years of education have reduced the need for genetic mechanisms that ensure gender differences? The idea that we propose in our new article .

Rich heritage

Evolutionary biologists recognize that offspring do not just inherit genes . It also inherits all kinds of resources : ecology, nest, parents and peers. And it seems that these sustainable environmental factors can help ensure reliable reproduction of the trait in different generations.

Take, for example, the “instinctive” sexual preference of the sheep and goats of their species' partners.

It is noteworthy that this adaptive behavioral trait seems to depend in part on early contact with the animals of their own species. It was found that male sheep and goats grown in a group of other species develop sexual attraction to them.

In this case, genetics is not the only inherited resource for development: a stable environment in which sheep grow with sheep also matters.

Rethinking Genetic Mechanisms

We suggest that an environment that teaches men to be men and women to women can make genetic mechanisms in some sense superfluous.

This helps to explain what would otherwise seem very surprising: we can breed sheep that are attracted to goats in one generation. But perhaps this should not be so amazing. Only a regular intersection of the species will provide them with genetic insurance for their sexual preferences.

Genetically determined traits can be lost when some reliable environmental feature makes them unnecessary. One example is the loss of the ability of primates to synthesize vitamin C , since this vitamin is readily available in their fruit-based diet.

We do not claim that the examples we cite can be generalized to different types or behavioral traits: this is a matter of empirical research. But understanding that stable environmental conditions can play a crucial role in the development and inheritance of adaptive behavioral traits is very important for people.

The influence of the human environment

The human environment includes extensive cultural, behavioral and environmental mechanisms for transferring gender traits.

We emphasize gender differences with names, clothes, and hairstyles. We learn about them from the beliefs, judgments, behaviors and demands of family, friends, celebrities, the media, art and science. People have an unprecedented ability for social learning , which means that most of us easily absorb these lessons.

A recent study by Melissa Heins' lab shows that gender can affect who we learn from.

The study showed that girls with congenital adrenal hyperplasia (VGN) exposed to unusually high levels of androgens (a group of steroid hormones that include testosterone), show a decrease in the tendency to imitate the behavior of women and "obey" the sex.

This may explain the greater interest of girls with VGN in “boy games”, the observation often used in support of the fact that boys and girls prefer playing games because of higher prenatal testosterone levels in boys.

The study of Heins shows the possibility that, to some extent, sex through testosterone affects the person from whom we learn, but the environment determines what we learn. If the environment is gender, our preferences for toys will also be.

Brain like mosaic

At first glance, the idea that sex is not necessarily the only way to transfer traits between generations seems inconsistent with evidence. Studies show that the genetic and hormonal components of sex influence the structure and function of the brain.

However, recent studies in rats on the effect of sex on the brain show that these effects can vary and even be opposite in different environmental conditions, such as different levels of stress.


These interactions between sex and the environment, which can also be different in different parts of the brain, produce a brain consisting of unique “mosaics” . Such mosaics have recently been found in humans .

In other words, gender affects the brain, but this does not mean that there are two different types of brain - “male brains” and “female brains”. Although you can predict the sex of a person with an accuracy higher than the probability based on the mosaic of their brain, an attempt at reverse prediction — the prediction of the unique mosaic of the human brain based on the shape of their genitals — would be more difficult.

Returning to gender disputes

The possibility that the main role of our genetics is to shape gender from the culture around us supports organizational initiatives in favor of gender balance.

The flip side is that the prevalence of “gender” environments means that many aspects of the environment must change in order for gender patterns to shift at the population level.

Those who work to increase the number of women in technology and leadership must work a lot. However, people are unique in their ability to transform the environment.

A century ago, our gender disputes focused on whether women needed higher education and voting. Today, such disputes are ridiculous due to the development of social relations and science. Now they are talking about technology and leadership.

As history has shown, when cultural ideas about what roles women and men perform “better” change, the actual roles of women change over generations .

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