Do We Inherit or Create Our Personalities? A Review and Analysis of the Evidence

Abstract

There has been an ongoing debate about whether personality is inherited through genes or created through the environment. This article addressed the issue by analyzing three research articles about the heritability of a particular personality trait through research methods, limitations, and known information. Common patterns and trends seen in the three articles were then investigated and applications of the studies, as well as the relevance of those studies, were examined. The first study is a twin study that examined the heritability of the environmental sensitivity trait and examined its genetic overlap with traits in the big 5 personality traits. The second study is a molecular behavioral genetics study that examined how dopamine-related genes and environmental factors such as stressful life events and parental warmth contribute to the development of a highly sensitive personality. The third study is a longitudinal sibling study that examined how parenting behaviors can affect adolescent responsibility and young adult conscientiousness. From the three studies above, it is clear that in general, personality traits have relatively high heritability. However, genes are not the only thing that influences personality. Non-shared environmental factors also contributed significantly to the development of personality, especially to the variations of personality traits. Certain genes may be expressed only when an environmental condition is met. It is the interaction between genes and the environment that shapes the development of personality and makes individuals who they are.