What is an introvert and what is an extrovert? Extroverts derive energy from being around other people (extroversion) while introverts recharge by being alone with their thoughts (introversion). Swiss psychiatrist Carl Jung first described these personality types in the 1920s. Many people are a blend of the two (called an ambivert). An AncestryDNA^® Traits test can tell you if people with DNA like yours tend to be more extroverted or introverted.

Introvert vs. Extrovert: A Closer Look at How They're Different

Most people have an idea of whether they are an introvert or an extrovert (also spelled extravert). But the terms are sometimes misunderstood. Introverts tend to enjoy spending time alone, or with one or two people they feel close to. They are quietly contemplative, often turning ideas around in their head before speaking. Extroverts tend to work their ideas out by talking them through with others. They thrive on the stimulation that can come from being around other people and from crowds. An extrovert may be called a people person, while an introvert may be called a thinker.

Being an introvert isn't the same as being shy or being afraid of people. Likewise, being a performer doesn't necessarily mean you're an extrovert. In fact, performing can be a safe way for introverts to express themselves and share their ideas with the world. Knowing your personality type may help you understand what you need in your personal life as well as in the workplace. For example, an introvert might need time away from social settings in order to think, while an extrovert might not feel confident about an idea unless they can talk it out. But many people have some personality traits of each, making them ambiverts, which means somewhere in the middle.

The Genetics of Introversion and Extroversion

Many traits have specific genes or markers. But there is still a lot we don't know about the genetics of personality traits. That's why Ancestry looked at the DNA of more than 185,000 people who voluntarily answered a survey question about introversion and extroversion. Then, we compared the DNA of those who said they were introverted versus those who said they were extroverted. We found more than 10,000 DNA markers associated with introversion and extroversion and created a Polygenic Risk Score that predicts the likelihood of each result.

According to Dr. Marti Olsen Laney, some research suggests genetics can play a role in shaping your personality by impacting how much of certain brain chemicals you have and how they are transmitted. For example, genetics can impact how sensitive you are to some of these brain chemicals. Still, there are a lot of factors other than genetics, like your environment and life experiences, that can significantly impact your personality.

What Else Does Science Say About Introversion and Extroversion?

A key brain chemical researchers are looking at regarding introversion and extroversion is dopamine. This chemical controls the feelings of reward and is responsible for that “rush" you get from novel experiences. For a particular study, researchers had study participants do a gambling task. Because they were looking at their brains in a scanner, they could see how brain activity differed between introverts and extroverts. When a gamble “paid off,” extroverts had a stronger response than introverts in the parts of the brain involved in the dopamine system.

Science gives us a window into other interesting tidbits about introverts and extroverts. For example, being extroverted has been linked to better sleep. Introverts also tend to use a different part of the nervous system when facing stress. Our sympathetic nervous system is responsible for “fight or flight," whereas our parasympathetic nervous system channels “rest and digest.” Introverts are more likely to rest and digest than fight or flight when confronted with a situation.

Interesting Facts About Introversion and Extroversion

Personality tests that help people understand whether they are introverts or extroverts are big business. The personal inventory and personality tests that HR professionals, psychologists, consultants, and dating sites use are a $2 billion industry. Proponents of these tests say they give us insight into our strengths and who we are. But critics say they can create tunnel vision and don't take into account how personality traits can change throughout life. Still, a scientific DNA test could show you whether your genetics might be playing some role in your introverted or extroverted personality.

References

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