Is personality inherited? How much of who you are comes from your genes versus your upbringing?
Steven Pinker’s nature vs. nurture argument shows up in his book The Blank Slate. He explores the scientific evidence behind personality inheritance. Pinker argues that our core traits are largely genetic, with upbringing playing a minimal role.
Continue reading to understand Pinker’s argument, and see whether you believe the debate is settled.
Is Personality Inherited?
Is personality inherited? According to Steven Pinker, the nature vs. nurture debate is essentially settled by scientific evidence. In his book, he examines what his scientific account of human nature says about human personality. Although empiricists contend that our personalities depend heavily on our upbringing and home life, Pinker instead argues that our personality traits are heritable and our upbringing plays little role.
Pinker maintains that twin studies show that all personality traits are heritable to at least some extent. He explains that, because these twins aren’t raised in the same environment, any degree of similarity between them can only have genetic origins. When tested for various core traits (like intelligence, neuroticism, and agreeableness) these twins consistently show heritability values of around 0.5, meaning that 50% of the variation in each personality trait has a genetic origin.
(Shortform note: Even if our core personality traits are partially determined by our genetics, personality experts point out that many such traits can subtly change over our lifetimes. For example, they note that it’s common for extroverted individuals to grow gradually more introverted over time.)
Pinker points out that, by contrast, similar studies have shown that our family upbringing has almost negligible impact on our personality. For example, studies of adult siblings’ personality traits reveal that these siblings are similar regardless of whether they grew up in the same household. Adopted siblings, on the other hand, don’t demonstrate a higher average degree of similarity than two random strangers.
| Non-Genetic Ways That Parents Influence Children Some researchers have critiqued the model used to arrive at the heritability value of 0.5. They explain that this number averages genetic and environmental effects across a sample of people, failing to account for how individual characteristics alter how genes and upbringing influence personality. For example, saying that the heritability of patience is 50% doesn’t mean that any specific child’s patience level is 50% genetic. When these researchers used a different model to estimate genetic and environmental effects on twins’ personalities, they found that teens’ perceptions of their relationships with their parents impacted to what extent genes influenced their personalities. This put the heritability of certain personality traits at a range of 20%-76%—higher for teens who felt their parents were proud of them and lower for teens who didn’t. Beyond the question of how parents influence children’s personalities, psychologists have found that parents shape their children’s attachment styles—how their children relate to others in close relationships. To illustrate, if parents are emotionally unavailable and cold toward their children, those children are much more likely to become avoidant in their later relationships, meaning they tend to crave independence and have difficulty with trust and intimacy. |
