Is personality inherited? How genes influence us

To what extent is the personality of fathers and mothers passed on to their children?

We have all heard expressions such as "he has his father's temper", "he is as kind as his mother", "his grandfather was also naughty when he was a child" and so many others like that.

That is why, since it seems that our way of being is something that runs in our family, To what extent is personality inherited? What is more important in defining it: genes or environment? How do we know? Let's look at it below.

Genetics and behavior: how are they related?

As with most animals, humans inherit DNA from our parents, half of which is made up of maternal DNA and the other half of which is paternal. This genetic inheritance influences various aspects, including our behavior, character and values.. However, and this is the point that differentiates us from animals, is that we are capable of setting goals and having aspirations, which can be promoted by the family and cultural environment in which we live.

Another difference that sets us apart from other animals is that we humans are aware of our genetic inheritance, that is, to what extent we are so similar to our parents, both psychologically and physically, and, resorting to free will, we can try to move away from what is supposed to be in our genes. This is the field of study of behavioral genetics.

Although it is known that behavioral aspects, both those that are adaptive and those that involve psychopathology, are to a greater or lesser extent heritable, a mistaken belief prior to the development of the Human Genome Project was that every behavior or aspect of personality and intelligence was delimited by one or a small group of genes.. However, research found that there was no single gene for, for example, schizophrenia, giftedness or the dimension of extraversion.

Each of these aspects, and virtually all human behavior, depends on the interaction of several genes, which may number in the thousands. Each gene has a miniscule impact on personality, but together they shape and resemble that of the parents.

Genes versus environment: who will win?

The influence of genes and environmental factors on an individual's behavior is highly variable throughout life. It has been shown that families, which are in themselves an environmental factor, have an important influence on children's cognitive abilities during early childhood. However, when these children have grown up and are old enough to attend school, However, when these children have grown up and are old enough to attend elementary school, it seems that genes take over, blocking environmental influences.blocking the influences of the environment.

Obviously, the assertion that six-year-old children are pure heredity and no environmental influence is false. Education at school, together with contact with other children and the experience of certain types of events, benign or unfavorable, mold their way of being and their knowledge, however, it is in these years that their genetic code seems to be more relevant in determining their personality.

In fact, between the ages of three and six, children try to find an environment that suits them, i.e., they select their friends according to the way they are, try to create an environment that is in line with their predispositions.. For example, a child with tendencies to be more active is likely to be interested in sports, which will motivate him or her to practice soccer in the schoolyard and have contact with other children who enjoy this activity.

Is personality inherited?

The approach to the heritability of personality has been carried out by the best type of study that behavioral geneticists could have achieved: twin studies, both with monozygotic or genetically identical twins, as well as with dizygotic or twins. These experiments are ideal, especially when identical twins have been separated at birth.. Those traits that they share, despite having been raised in different households, will be attributed to genetic factors.

Although this type of research still has some methodological problems, there are certain patterns in the results. The most powerful personality model at present is the Big Five model of McCrae and Costa, in which personality is defined on the basis of five major dimensions: extraversion, agreeableness, neuroticism, openness to experience and responsibility.

Studies that have studied the personality of twins, both identical and fraternal, indicate that there is a high heritability of traits, especially in the case of monozygotic twins. This means that if, for example, one identical twin is cordial, the other twin, with a high degree of certainty, will also be cordial.. This is a clear indication that personality is strongly influenced by genetic inheritance.

To what extent does genetics influence?

When we talk about something being encoded in the genes and being a product of heredity, we are referring to the concept of heritability of a given trait. Heritability indicates what percentage of variation in the traits of two individuals is due to genetic causes.. A high percentage of heritability indicates that the variation of the trait, for example being creative, is largely due to genes, while a low heritability means that environmental factors are more important.

Research suggests that the heritability of personality traits is around 40%-50%. This means that about half of the variation in personality can be attributed to a genetic component.

This should not be misinterpreted, since it does not mean that half of an individual's personality is due to genetic factors. The non-shared environmental factors would explain about 30% of the variation, and the shared ones about 20%.

What should be clear from the concept of heritability of personality is that it does not indicate that we have about a 50% chance of inheriting the personality of our parents, or that we will share 50% of that personality. The heritability data indicates that, for example, if one person is creative and another is less so, a good part of that difference is due to genetics and the rest is due to having received influences from the environment, both shared and unshared.

Heritability should not be confused with the idea of genetic determination.. The latter refers to the fact that genes can determine a particular trait, as long as it is known which gene or genes are involved in such determination.

Thus, when analyzing the extent to which a given personality trait is heritable through genes, we must keep in mind that we are not analyzing the probabilities of receiving that characteristic from paternal or maternal DNA, but rather This is a relative estimation, based on comparisons between individuals, and focusing on the variation between individuals.and which focuses on variation.

Moreover, it should be borne in mind that in many respects, cultural phenomena are so pervasive that they can easily be confused with something determined by genetics. For example, the degree of religiosity of people: for centuries, practically everyone in the world was religious to a greater or lesser degree, and only in recent times has it been seen to be a phenomenon closely linked to cultural dynamics.

In the same way, the influence of genetics on personality is not studied from the idea that a certain way of behaving is "natural" and is present in different degrees in all people due to genetic aspects, but it is taken into account that genes and experience are constantly interacting, even where it does not seem so.

Bibliographical references:

• Church, A. T. (2000). Culture and Personality: Toward an Integrated Cultural Trait Psychology. Journal of Personality, 68(4): pp. 651 - 703.
• Harris, J.R. (1995). Where is the child's environment? A group socialization theory of development. Psychological Review, 102(3): pp. 458 - 489.
• Jang, K., Livesley, W.J., & Vernon, P.A. (1996). Heritability of the big five personality dimensions and their facets: a twin study. Journal of personality, 64(3): pp. 577 - 591.
• Vukasović, T., & Bratko, D. (2015). Heritability of personality: A meta-analysis of behavior genetic studies. Psychological Bulletin, 141(4), 769–785. https://doi.org/10.1037/bul0000017
• Strobel, Maria; Tumasjan, Andranik; Spörrle, M. (2011). Be yourself, believe in yourself, and be happy: Self-efficacy as a mediator between personality factors and subjective well-being. Scandinavian Journal of Psychology, 52(1): pp. 43 - 48.