In my philosophy class, we’ve discussed two different theories of development: the continuous model and the traumatic model. The continuous model states that who we are as adults is exactly who we were as children – just physically grown. The traumatic model takes more of a Freudian perspective in that it posits that who we are is a reflection of the traumatic experiences we had as children. This discussing had me wondering. Is there any truth to either of these models? Is it possible that both are true, or perhaps even neither? What makes us who we are?
To begin my search I conducted a Google search of my question. Through this search, I came upon a few different studies. The first, as reported in the New York Times, cited a study conducted by the University of Minnesota. The results of this study found that personality traits are mostly inherited. From 1979-1986, 350 twins pairs underwent various forms of testing, ranging from drawing blood to taking a personality evaluation test. The conclusion of the study found that more than half of the test personality traits were hereditary, as opposed to due to the person’s environment. This is further backed up when considering that out of the 350 pairs of twins studied, 65 pairs were raised apart from each other. Yet, their personalities were still remarkably similar.
The next study I found, from Edinburgh University, corroborated the first study’s findings. The university studied more than 800 sets of identical and fraternal twins in order to determine what effects nature or nurture has had on these peoples’ success in life. The participants were asked a series of questions which were then analyzed to determine the traits of the people studied. The results found that identical twins were twice as likely as the fraternal twins to have the same traits, which suggests that DNA has a strong impact on personality. It is wise to remain skeptical though, as we have learned in class that correlation does not equal causation.
Although the two studies seemed credible, I wasn’t yet convinced. I tried to find evidence of a differing scientific opinion, however, I was less than thrilled with my discovery. Researchers at the University of Exeter and the University of Hamburg determined that environment plays a stronger role in shaping personality than genes, however, their study dealt with zebra finches and not humans.These finches were taken from their birth parents and placed in a foster environment. Researchers found that these foster finches had more of an influence on their children than genetics seemed to. Personality was more dependent on environment for these birds than genetics, although researchers did acknowledge that offspring size of these finches did seem to be genetically inherited.
Overall, it seemed that through the various studies I found, some not included in this post, corroborated the idea that personality is largely genetically inherited. However, this clearly isn’t the only thing that defines one’s personality. It is such a complex thing that encompasses many factors, so it is impossible to say conclusively in any of the studies that genetics is that only thing that makes up someone’s traits.