Why are some people naturally extroverted, while others are more anxious or reserved? And this pig character, where does it come from? Is it innate or constructed? For decades, scientists have tried to understand what shapes our personality. And contrary to some preconceived ideas, there is no “aggression gene” or DNA capable of predicting our character on its own.
Genes influence our personality… but only partly
For a long time, some researchers thought that a few genes could explain certain behaviors. The famous “warrior gene” (MAOA), associated in the 2000s with an increased risk of aggressive behavior, is the best-known example. But this vision is today widely called into question.
“Behaviors are not determined by one or two major genes”, explains geneticist Aysu Okbay, professor of psychiatry and complex trait genetics at Amsterdam UMC. The most recent work shows, on the contrary, that our personality is polygenic: it results from the combined action of hundreds, even thousands of genetic variations, each of which has only a minimal effect.
About half of our personality does not depend on our genes
Studies carried out on identical and fraternal twins make it possible to estimate the weight of heredity. A large meta-analysis published in 2015, bringing together more than 2,500 studies, concluded that 40 to 50% of personality differences are linked to genetic factors.
In other words, genes play an important role… but they only explain part of who we are.
The environment also matters… but not always in the way we imagine
We might think that a divorce, a bereavement or a dismissal would have a lasting impact on our personality. However, research shows that major life events often change our character less than we think.
According to Brent Roberts, a professor of psychology at the University of Illinois, even major trauma in adulthood usually does not profoundly transform the personality. On the other hand, repeated childhood experiences seem to have a more lasting influence, particularly when they concern the expression of emotions or emotional security.
Some studies even suggest that the environment begins to act before birth. The stress experienced by the mother during pregnancy could influence the temperament of the future baby via so-called epigenetic mechanisms, which modify the expression of genes without changing the DNA itself.
Our character is built very early
For Emile Guibert, doctor of psychology interviewed recently by True Medical, the basic temperament is present from birth, but its expression depends largely on education and early experiences.
“Temperament remains largely inscribed from birth and relatively stable throughout life”he explains.
On the other hand, the way in which parents receive their child’s emotions plays an essential role. An impulsive child can learn to better manage his anger if given the right tools, while a child whose emotions are constantly repressed is more likely to internalize them.
Can you change your personality?
Good news: even if our temperament remains relatively stable, our personality is not fixed.
For Emile Guibert, it is entirely possible to learn to better manage your reactions through work on yourself, psychotherapy or certain life experiences. An anxious person may never become completely carefree, but they can develop new strategies to better cope with stress. Everything is therefore not frozen in time.
Researchers today agree on one point: personality is born from a permanent dialogue between our genes and our environment. No single gene decides whether we will be shy, optimistic or impulsive. In the same way, an isolated event is generally not enough to lastingly transform our character.
Our personality is the result of a multitude of small biological, familial and social influences that accumulate over time. Good news, ultimately: if we do not choose our initial temperament, we retain real room for maneuver to evolve and learn to know ourselves better.