Are You Born an Introvert, or Do You Become One?

Introverts are finally getting our time in the sun. There are more websites, books, and communities for introverts than ever before—enough that young introverts can grow up understanding themselves, instead of feeling “wrong” like I did as a kid. But there’s no shortage of people who still don’t get it. Anytime I mention I’m an introvert, someone asks something like, “Why can’t you just learn to be social like everyone else?”

That viewpoint is backwards, but it does raise a good question. Do people “learn” to be introverts as they grow up, or are we introverts from birth? In other words, what makes you an introvert—your genes, your upbringing, or some mix of both?

The Science of Young Introverts

To answer this question I turned to Dr. Marti Olsen Laney’s book The Hidden Gifts of the Introverted Child: Helping Your Child Thrive in an Extroverted World. Laney gives a detailed rundown of what we know about young introverts, including the specific factors that cause them to be introverted in the first place.

Like most questions of nature versus nurture, Laney tells us that the answer is a little bit of both:

“Yes, children are born with an innate temperament. And yes, parents are vitally important to how that temperament is nurtured.”

But she emphasizes that introverts are (mostly) born that way. Specifically:

  • The degree to which you are introverted or extroverted is influenced by genetics.
  • Out of all the personality traits that have been studied, introversion/extroversion is one of the most strongly hereditary ones.
  • Nonetheless, a lot of environmental factors—like how you’re raised—influence it too.

These aren’t guesses on Laney’s part. She pulls together some of the best neurological research on introverts to show exactly how genetic it is—and why some factors can defy your genetic “programming” to change your disposition.

The Genetic Basis for Introversion

Laney says the basis of being an introvert lies in our biochemistry. Human brains have a mix of over 60 neurotransmitters, chemicals that determine exactly how the brain works. While those chemicals are largely the same from person to person, we each have slight differences—our own “recipe.” Your recipe is determined by your genes, and is with you from birth. It also determines many personality traits, such as your tendency toward introversion or extroversion.

This correlation is so strong that Laney says children show their introversion/extroversion tendency from the moment they’re born.

The most important of these neurotransmitters is dopamine, which rewards you for pursuing external rewards. Introverts’ brains are far less driven by dopamine. We don’t get the buzz from it that extroverts do, so we don’t seek as much external stimulation.

Our dopamine sensitivity is an example of our neurotransmitters in action—and it’s determined by our DNA.

How Genetic ‘Set Points’ Make You Flexible

Introversion isn’t totally genetic. It gets influenced by your environment at a young age, and our genes allow a certain amount of flexibility in response. This happens through “set points,” which are the upper and lower limits of how much extroversion your brain can handle.

Laney compares these set points to setting a temperature range on a thermostat. You might program your thermostat to keep your house between 68 degrees and 74 degrees Fahrenheit. Within that range you’re comfortable and no climate control is needed. But if it gets too cold or too warm, the heater or AC kicks on and you have to spend energy to get back to the comfort zone.

The brain works the same way. As an introvert you might want more social time one day and less another day, and as long as you’re within your “set points” you’re okay. But if the stimulation takes you beyond your upper set point—maybe by going to a big birthday party—we all know how drained you’re going to feel.

That means two introverts with the same genetic disposition could come across quite differently. One might stay closer to the high-stimulus end of their comfort range, while another stays cautiously at the low end. These behaviors are largely learned through experience. If a child gets enough positive experiences with social time, they might enjoy pushing the top of their range, even though they’re an introvert. A child who has negative experiences could develop more reclusive, quieter ways.

A Portrait of Three Kids

To see how this works, let’s look at three hypothetical children. All three are introverts, but they’re not all the same:

  • Jen and Amanda are identical twins. They have the same DNA and very similar brains at birth. Both show signs of being introverted, but their “set points” are quite wide. They could act more social or more introverted on any given day.
  • Matthew is also introverted from a young age. However, his brain has fairly narrow set points, much narrower than Jen and Amanda’s.

Despite being all introverts, the children turn out very differently.

Jen has some early positive experiences that reward social activity. She’s older than Amanda by several hours, and people always ask if she’s going to be the “leader” of the two. When she does something bold or showy, adults laugh and cheer. This positive encouragement makes it fun to stay toward the top end of her set point range and be a social introvert.

Amanda has the opposite experience. When she does something showy, adults say she’s copying her sister. She doesn’t find it rewarding to come out of her shell as much. By the time she’s old enough for preschool, she isn’t as excited about making friends as Jen. Other kids stare at the twins, and she takes this attention as negative. She’s happier when she stays near her lower set point. She’s considered the shy one.

Matthew has a different upbringing. He’s an only child and his parents give him a lot of positive attention. They can see his introversion early on, and instead of being critical, they try to gently encourage him in social situations. They take him to the playground, join a play group with other families, and put him in a private preschool that encourages creativity.

But Matthew stays introverted. Even though his group experiences are positive, he has a very low set point for external stimulus. He comes back from play dates cranky or sleepy. He’s well adjusted socially, but he prefers inner, imaginative activities to people time.

So Are You Born an Introvert, or Not?

These children are imaginary, but they correspond to patterns that many of us have lived in real life. Your genes give you a “range” of introversion. A wide range could be heavily influenced by how you were brought up, but a narrow range means upbringing won’t change you as much. This is why Laney says the answer to the nature vs. nurture question is, “Yes… and yes.” Your genes make the choice, but they can make you flexible, too.

What’s clear is that your preference for introversion or extroversion gets fixed early on. As much as your experiences might shape you, Laney says most children stay true to whichever preference they showed in the first four months of life.

I can clearly see experiences in my own life that helped give me my strong introvert tendencies, such as being a misfit at school. I also wonder if I might have a “narrow” range of set points, more like Matthew than Jen and Amanda, as I can happily spend weeks at a time with no social contact. retina_favicon1

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  • Deanna says:

    This is so interesting, and I think it makes sense! After observing people in introvert groups, I’ve noticed that while I do relate to a lot of what people post, I also have begun to more clearly see the differences between types of introverts, and I think that the idea of set points is one way of accounting for that. I think I have a wider range because my love of genuinely connecting with people causes me to be busy and engaged with people-I often say that I am an introvert with the schedule of an extravert, but most of my activities promote a more introverted way of connecting (i.e. more one-on-one or small groups and fewer parties!)

  • giroliddy says:

    Thank you for the article – very interesting. The other thing I’ve noted is a Myers-Briggs thing. It strikes me that I**Js (with the exception of the INTJ) often tend to be far more sociable than I**Ps, who can easily tolerate (in fact, crave) extended periods of complete solitude. I wonder if their judging preference means that they have a need to feel that they are in sync with their surrounding social system. The perceiving types won’t give two hoots about that. It would make the I**Js naturally more sociable than the I**Ps.

    • Hmm. Interesting Giroliddy. I would say I know older ISTJs (all men) who are extremely unsocial. I can’t speak to younger ISTJs because I know only one, and while she is friendly, she focuses 98% of her time on work.

      But INFJs and ISFJs are very social introverts.

      • giroliddy says:

        Agreed, they are indeed. The ISTJs I happen to know are certainly considerably more social than the ISTPs I also know. But yes, I take your point. ISTJs have great “grumpy old man” potential!

  • JaydeRubee says:

    This is fascinating information. I’m an INFJ and I would say I have a broader range of set points. While not mentioned in this article I’m sure it is understood that “set points” also apply to extroverts. My husband is an ENFP and he seems to have a more narrow range of set points on the extroversion scale. Because of this we end up being closer on our preference for social interaction. We make an interesting combination–I, an outgoing introvert, and he, a reserved extrovert.

    • Jay – you’re right. In Laney’s work she does make it clear that everyone has set points for external stimulus, extroverts included. Interesting observation about you and your husband. I wonder if INFJs in general have wider set points, since they spend so much time tuned in to how other people feel.

  • Kathleen Lyons says:

    Interesting article. When I was little and had playmates over for awhile, I’d go tell my mother that I wanted my friends to leave. I was told that isn’t polite. As an adult, I enjoy being with friends, but I need my alone time, too. When spending time with people, it’s quality time, not quantity.

  • Rhona says:

    It is an interesting article. I wonder if, because I love to connect with people and hear their stories (INFP) I tend to hang about at the top of my set point, and sometimes go over it, getting ‘burnt out’ suddenly and without warning. Because people think of me as social they are surprised when my brain switches off and I disengage. I find it quite annoying not to be able to predict it.

  • This is interesting for me because for alot of my life I was more of an Ambivert (specifically up to adolescence) with my parents both being quite Extroverted but later on I began to become more and more Introverted which shows that genetics isn’t everything!

  • Megan says:

    Interesting article! I don’t quite understand the science behind the “set points”. This is the first I’ve read about that, so I’ll have to look into it more.

    I think INFJs and ISFJs appear more social because of our Extroverted Feeling function, as well. I can spend days without talking to anyone and be perfectly content, but when I’m in a group I might appear more social compared to an ISTJ, for example, because I want to make other people feel comfortable and can tell that when I’m quieter, people (in general) feel less comfortable around me.

    It seems almost like the idea of set points has less to do with introversion and extroversion, but how outgoing or quiet/shy someone may appear? I may be a social introvert, but still feel just as drained as the quiet introvert at the party.

    • Megan, imagine the set points as a range of how much social time you enjoy/need. For example, let’s say we could rank everyone’s social needs on a scale of 1 to 100, where 1 means you are a total hermit and 100 means you enjoy talking to people 24/7.

      On that hypothetical scale, the idea is that one introvert might have their bottom “set point” at 10, and their top “set point” at 30. As long as they can get 10 to 30 points of social time per day, they are happy. If they get less than 10 they feel lonely, but more than 30 makes them feel exhausted.

      A different introvert might need at least 20 points, but can deal with up to 45 points happily. This is the important thing about set points – different introverts have very different ranges, and some of us a “more” introverted than others.

      An extrovert, on the other hand, might need at least 60 points of social time per day but can take up to 95 without getting exhausted.

      That’s the way I picture it.

  • Matie Leaves says:

    I was always an introvert (INFP), but until I was four I loved to go on adventures by myself. We lived in a small town while my father was away during WWll, and I used to take off and walk downtown by myself or try to climb the local “mountain.” Then we moved to the capitol city and the first kids I met told me they were going to hang me and that was that. No more peeps for me! So I guess that a pretty narrow set point. But I knew that, already, if not the term.

  • samir64 says:

    This range of introversion concept is quite interesting and true. I think I have a range too but its not much wide either, if not much narrow. What I’m even more interested in knowing is if I can push myself out of this range if I want to. Upbringing is an experience in the real world. What if I change my experiences by changing my environment? will it do any good in pushing myself out of introversion range? will it hurt me, if I did?

  • Liz Thirose says:

    Thanks for this very interesting text. I was looking for something that might help my mum understand. She’s always complaining about me being “like that”, and how did I become it. I guess she thinks she and my dad did something wrong, and it seems to be beyond her understanding that it’s just the way I am; that I am happy when I’m alone or do things alone (she’s the total opposite and thrives on social contact). I might just translate (we’re German) and give that text to her, maybe that’ll help her a bit.
    As for the question at the end– I believe my range is wide, in theory. I can cope with quite a lot of social interaction for a short time, but it drains me. I have had positive experiences with adults when I was a kid; however, my experiences with kids my age were mostly negative (I was bullied most of my school years and had two or three friends, tops, that whole time).
    So even today – being 30 now – I prefer interacting with people older than me, if I have to interact with anyone at all. I often notice myself being very cautious around people my age or younger, which in turn is even more draining. Generally, however, I prefer to just be alone, with myself and my hobbies. I like being with my partner, but even that can be exhausting at times; and after work, where I sit in a huge office with over 30 people I usually only feel good, if not “alive” again the moment I close my apartment’s door behind me and shut the world out.

  • Guest says:

    So basically, it depends a lot on whether one gets support and understanding from friends and family.

    Of course I don’t remember my personality when I was four months old, but at a young age I was a goofball, always making up stories — noted on a Christmas card by my dad when I was 3 years old — but later in life when I was teased and laughed at at school, and didn’t get support from my parents, well, that’s when I started to think something was wrong with me.

    50 years later, still trying to accept myself as I am.

  • Gwen Howard says:

    I’m an introvert and until just a few years ago I thought something was wrong with me because too much social activity wore me out and made me reclusive. I Googled information on my symptoms and to my relief found a wealth of information on introversion which not only put a name to the characteristics but assured me that I wasn’t just weird or crazy as some have called me. After reading your article I realized that I have a narrow tipping point which was developed because I spent a lot of time alone growing up. Although I had 2 brothers they were extroverts and never around. Both my parents worked so I was often on my own as a young child and teenager. Thank you for sharing this information.

  • Ace Amy says:

    Sources??? Please?