Nature v Nurture Revisited: What’s Behind Your Myers-Briggs Personality Type?

Are we born with our personalities, or are we shaped by traits that reflect our upbringing, environment and relationships? Psychology has been trying to answer this for decades—the age-old question of nature versus nurture. 

At some point, almost everyone questions whether their Myers and Briggs type has more to do with one end of the spectrum than the other. If you are the exact same type as one or both of your parents, you may suspect an innate genetic inheritance from your gene pool. Or perhaps you’re so very different from your parents and siblings that you can’t understand how you all come from the same family tree. What could be causing such striking differences between family members who share the same DNA?

Here’s what we know about nature versus nurture, and how that correlates with your Myers and Briggs type. 

The Nature v Nurture Debate

Although psychology is still a relatively new field compared to other scientific fields, the question of nature versus nurture is much older. As far back as ancient Greece, Plato and Aristotle were debating whether children inherited their parents’ personalities. Plato tended toward nature theory. He proposed that some things are inherent in an individual, regardless of any outside influence. Aristotle, on the other hand, believed that people begin as a “blank slate” and are shaped solely by their environment and experiences. 

Some years before Sigmund Freud began his career, Francis Galton, the famous eugenicist and Charles Darwin’s cousin, coined the term “nature versus nurture.” Galton believed that intelligence and almost all other traits were thanks to genetics, and he suggested people should improve the human race through selective breeding—yikes! 

Thankfully, Freud helped shift the scales to nurture, as did the behaviorism movement in psychology. Behaviorism is a school of thought that argues that all behavior is learned through interactions with the environment, mostly via conditioning such as rewards and punishments. 

The history of the two extremes isn’t always rosy, as you can see. But most evidence today suggests that both are important, and nature and nurture work in tandem to shape who we are. 

Evidence for Nature 

Do you ever look at a sibling or parent and think, “Gosh, it seems like I’m just like them?” Similarities between your personality and your immediate family should come as no surprise, and you may owe some of this to your gene pool.

Studies with twins are revealing. For instance, researchers from the University of Minnesota measured the Big Five traits of 350 pairs of twins, some of whom were raised separately and others together. This groundbreaking study found that identical twins raised apart were just as similar as twins raised together. Specifically, the study found that about 40% to 60% of the ways the twins were similar in their personalities—such as being outgoing, organized or anxious—could be traced to shared genetics, with the rest coming from their upbringing and environment. A meta-analysis of 50 years of twin studies found a similar link—about 49% heritability of personality traits. 

In another fascinating study based on Finnish, German and Korean samples, researchers found that character is 50% inheritable. They identified over 700 genes related to one’s empathy and self-reflection capacity, neurodevelopment, stress regulation, neuroplasticity, memory, and energy metabolism.

Another study specifically measured the heritability of Myers and Briggs preferences by examining 61 pairs of identical twins and 49 pairs of fraternal twins, all of whom were raised separately. This study found that roughly 60% of the variation in Extraversion and Introversion and Thinking and Feeling could be explained by genetic factors. In other words, if one twin was an Introvert, there was a higher likelihood that the other twin was also an Introvert.

Evidence for Nurture 

How much, then, does your environment shape you? While you may have specific preferences from an early age, your upbringing also plays a role. A 2015 study found that you might be more likely to inherit two Big Five traits (Neuroticism and Openness) but not the other three (Extraversion, Agreeableness, and Conscientiousness). For those three traits, other factors seem to be in play.

Another study, which examined the socioeconomic status and culture of a person’s family and their preferences in the 16-type system, found that the environment seemed to determine whether someone was an Extravert or an Introvert. What exactly is meant by this is complex, however? For instance, we know that:

• Early childhood experiences (especially adverse ones) can help shape your personality traits. Facing adversity at a young age, for example, may increase someone’s Neuroticism and lower their Conscientiousness on the Big Five. 
• Parenting style plays a role in personality development. Permissive parenting (a parenting style with a lack of discipline or exceptions for their children, like a more extreme version of gentle parenting) may provide a child with too much freedom, causing them to struggle with self-regulation as an adult. Meanwhile, children whose parents use authoritative parenting are often better at self-regulating.
• School experiences can affect your personality development and emotional responses, especially one’s impulse control.
• Birth order can affect your personality and the stereotypes we have around first-born children being bossy and the youngest being rebellious are largely true. 

All of this to say, while the evidence might point to a certain level of genetic factors playing a role in your Myers-Briggs personality type, there’s just as much evidence that your environment, parents, socioeconomic background, school experiences and so on, also contribute to your personality type.

Nature and Nurture Work Together to Form Your Personality Type 

All the current research seems to point to the answer that nature and nurture play a role in personality development. Your traits are born of a complex web, interwoven by your genetics, environmental factors, parental influence and all of those little life experiences. 

So yes, you might have inherited your Introversion (or maybe not)! You may indeed have innate tendencies that your parents noticed when you were just an infant, but you also developed some of your personality traits over time as you interacted with the world around you.

Additionally, while your core personality doesn’t change much over time, some parts of it will mellow with age, and you can learn and grow from new experiences and develop specific tools you didn’t rely on before. For example, if you got a job as a tour guide, you might discover that you can easily appear Extraverted, even if you’re an Introvert.

The truth is, scientists still don’t fully comprehend how genetics interplays with our personalities. But one thing is clear: you’re uniquely you. While another person may share your Myers and Briggs type, your unique experiences and genetics make you an individual.