From Popular Delusions, a blog by Honors Intro to Psychology students
It’s All in Your Genes, Right? | Popular Delusions (wordpress.com)
Have you ever heard that you can’t change who you are because of the genes that come from your parents? Well, you would be lumped into a group with the many people who also believe that myth. Because it is a common myth, a simple Google search gives you many articles that include misinformation about heritability and the impact of genes. People may misinterpret how genes influence behavior and write about them, such as this article that lists 27 things that are supposedly inherited from your parents.
Simply defined, heritability is a measure of differences in traits across people due to genetics. If a trait is 100% heritable, the differences are completely controlled by genes across people. If it is 0% heritable, differences are completely controlled by the environment across people. If it is 50% heritable, then 50% of their differences are due to genes and 50% of their differences are due to their environments.
Despite the importance of DNA, heritable traits can be changed. For example, PKU is a 100% heritable disorder that can be fatal if phenylalanine, an amino acid found in many foods, is in the diet of an individual with this genetic disease. By changing the diet to avoid foods that contain phenylalanine, the individual avoids the harmful effects of the disease, and as an effect, changes their inherited genetic trait. Another example of this is the relationship between uncontrolled eating, body mass index (BMI), and genes (Vainik et al., 2019). BMI is a measure of a person’s weight divided by their height to give a good estimate of their body mass. Uncontrolled eating is strongly influenced by genetics and has been found to be heritable, but also is susceptible to environmental factors, such as the availability of unhealthy snacks and daily exercise habits. Having a higher BMI or increased food intake due to the environment one lives in increases the likelihood that one will experience uncontrolled eating in their life. The inherited genes that control these aspects of health can be changed due to an individual’s environment and the way they decide to live.
So don’t be worried if you think your fate is determined only by the genes your parents passed down to you. You can have some control of your heritable traits if you are given a set of genes you want to change.
References
Lilienfeld, S. O., Lynn, S. J., Ruscio, J., & Beyerstein, B. L. (2009). 50 great myths of popular psychology: Shattering widespread misconceptions about human behavior. John Wiley & Sons.
Vainik, U., García, G. I., & Dagher, A. (2019). Uncontrolled eating: a unifying heritable trait linked with obesity, overeating, personality and the brain. European Journal of Neuroscience, 50(3), 2430–2445. https://doi.org/10.1111/ejn.14352
