Genetics And Behavior: Do Genes Decide How We Act?
The human body is the result of millions of years of evolution of the material found in the nucleus of cells: DNA. Genes are the units of information that this genetic material has and the translation of the genetic code is expressed in characteristics, whether physical (eye color, hair type or nose shape) or psychological (behavior or personality).
But does everything depend solely on genes? That is to say, Are we what we are and behave the way we do because our DNA tells us to be that way? The answer is no. The environment that surrounds us has something to say about it. Human nature is very complicated, but every day we are closer to understanding it.
Using twins for studies has been a great tool that scientists have been using for years to understand how genes and the environment influence each person differently. The idea is to look at the extent to which it is upbringing or genes that serve to better predict the regularities that can be found in the development of the organism and the repertoire of habitual behaviors.
Twin research shows strong evidence of when and how genes and environment shape human nature. Some of them reveal that the importance of genes can change drastically depending on the stage of life we are in. Genetic influence tends to increase over the years in many characteristics s, as has been seen with body weight.
In another area, research with twins has been important in the field of molecular genetics. The best known is with body weight. Thanks to this type of studies, it has been possible to identify almost 100 genetic variants involved in obesity.
But the effect of genes does not have to be limited only to how our body is formed; It also explains how certain psychological predispositions appear For example, it is believed that we make choices in search of an environment that favors our predisposition to express genetically inherited strengths. A teenager who is genetically good at reading will probably start going to a library in search of more books. There he will meet people who think similarly to him and may begin to interact with them.
Likewise, IQ is largely heritable and it is difficult to modify it in a significant and sustained way through exercises and new learning.
The fear of genetic determinism
Studies with twins are a great opportunity to understand when the environment has more force on us and when behavior is easier to shape.
However, in the field of psychology and cognitive sciences, have been involved in controversy Critics of twin research question whether psychological characteristics, such as mental health, have a strong genetic basis. This is partly due to a fear that everything we think, feel and do is little more than the consequence of genes doing their job and condemning us to a life we cannot change.
However, this fear is unfounded.
Genes are not everything
The influence that genetics has on human characteristics is often misunderstood It is wrong to assume that a behavior that has a strong genetic influence must be innate by obligation. Genes are not everything; A gene will be expressed depending on the environment, that is, it can show its effects or not have any, depending on the environment in which we live.
With an example it will be clearer. There are people who are predisposed to lung cancer due to their genetics. Unless they smoke or constantly breathe tobacco smoke, they are unlikely to develop the disease. And this same thing is being seen with behavior. Behavior is obtained as a response to an environmental signal
Although some forms of behavior have a genetic basis, this does not imply that this predisposition will cause our brain to be designed in such a way that we manifest these behaviors regardless of the way in which we interact with the environment. Although our DNA cannot be modified through experiences and learning, the expression or not of its genes depends largely on the environmental conditions in which we live. For example, studies in relation to schizophrenia (a mental illness with a strongly heritable component through genes) show that the expression of the disease is greater when living in a context that produces stress.
Does knowing the genetic basis imply danger?
One of the fears generated from this work is that, by recognizing that behavior has a genetic basis, people will no longer be equally responsible when it comes to committing to healthy behaviors and the education of their children.
However, knowing one’s own predisposition to suffer from a mental or other type of illness does not have to lead to a loss of interest in improving one’s health, on the contrary, you gain a commitment and motivation to change your behavior and habits
