This Is the Scientific Explanation for Why Introverts Like Being Alone

As an introvert, I need plenty of quiet downtime. If I spend too much time socializing — or am just “out and about” too much in noisy stores or coffee shops — I don’t feel like myself. I get mentally drained and even physically tired. I get cranky and short with people. Every little annoyance, like a crying baby in public, seems magnified. I fantasize about holing up in my apartment for a day or two to recharge my energy.

Recent research shows that extroverts get worn out by socializing, too. So it’s not just introverts who need to rest after chatting and meeting new people. Nevertheless, there are some real differences between introverts and extroverts. On average, introverts really do prefer solitude more than extroverts, and extroverts are more driven to engage in social interactions that elevate their social attention and status (more about this later). So, scientifically speaking, why do introverts need more solitude than extroverts? The answer is found in the wiring of our brains.

Introverts Respond Differently to Rewards

One of the reasons introverts enjoy alone time has to do with how introverts respond to rewards. Rewards are things like money, sex, social status, social affiliation, and even food. When you get promoted at work or convince an attractive stranger to give you his or her phone number, you’re gaining a reward.

Of course, introverts care about things like earning money, eating, and having relationships, too. But researchers hypothesize that introverts respond differently than extroverts to rewards. When compared to extroverts, introverts are less engaged, motivated, and energized by the possibilities for rewards around them. So, they talk less, are less driven, and experience less enthusiasm. In fact, they may find levels of stimulation that are rewarding and energizing for extroverts to be tiring or annoying.

What makes introverts less motivated by rewards? It was to do with a chemical found in the brain called dopamine. Dopamine helps control the brain’s pleasure and reward centers. It enables us to notice rewards and take action to move toward them, and it reduces the “cost of effort,” meaning, it increases how much a person is willing to work for the possible reward.

When writing my upcoming book, The Secret Lives of Introverts, I spoke with Colin DeYoung, a psychology professor at the University of Minnesota who recently published a paper on introversion. He told me that extroverts appear to have a more active dopamine reward system than introverts. This means that extroverts’ brains become more active at the sight of a possible reward, and dopamine energizes them to pursue that reward. Introverts’ brains just don’t get as active as extroverts’ at the expectation of a reward.

 Why Introverts Enjoy Alone Time

Thinking about introversion in terms of rewards makes sense. Because introverts care less about obtaining rewards, we’re less motivated to do things that extroverts find immediately rewarding, such as socializing. DeYoung told me:

“Introverts are indeed often drained by socializing, but that’s partly because the effort required may not seem worth it because the rewards from socializing seem less to them. Extroverts get drained by socializing too, but they are more motivated to engage in it anyway, and it probably takes more socializing before they start to feel drained. Anything that involves expenditure of energy will be draining eventually.”

To fully understand what DeYoung is saying, imagine two friends — one an extrovert, the other an introvert — at a house party on a Saturday night. They’re crammed in a small room with thirty other people. Loud music blasts from huge speakers, and a few people are playing video games on a big screen TV. Everyone is practically shouting to make their voice heard over the din. There are a dozen conversations going on at once, and a dozen things to pay attention to.

For the extrovert, this “level of stimulation” might be just right. He sees possibilities for reward everywhere — an attractive stranger across the room, potential new friends, and people who will give him the social attention he craves. He feels energized and excited to be at the party. So motivated, in fact, that he stays late into the night. He’s worn out the next day and needs some downtime to recover, but to him, the energy spent was well worth it.

The introvert, on the other hand, finds this environment tiring and punishing. It’s too loud, there are too many things to pay attention to, and all the people in the room create a dizzying buzz of activity. The introvert simply isn’t interested (to the same degree as the extrovert) in the possibility of social rewards around him. The introvert makes up an excuse and gets out of there. He heads for home, where he watches a movie with his roommate before going into his bedroom to read alone. In his own apartment, alone or with just one other person, the level of stimulation feels just right.

Extroverts Are More Stimulated by People

Finally, a recent study found that extroverts are more stimulated by seeing people but introverts paid more attention to inanimate objects. The researchers studied a group of different people and recorded the electrical activity in their brains through an EEG. As participants were shown pictures of both objects and people, the researchers evaluated their brains’ P300 activity. This activity happens when a person experiences a sudden change in their environment; it gets its name because the activity happens within 300 milliseconds. Interestingly, researchers found that extroverts who saw pictures of flowers and faces achieved the P300 response from viewing the images of faces, while the introverts only had the P300 response from pictures of flowers. This doesn’t mean that introverts dislike people, but what it could mean is extroverts place more significance on people than introverts do.

 Are You Getting Enough Alone Time?

As an introvert, it can be hard to get enough alone time. You may feel guilty when you decline a social invitation or tell your significant other you want a night to yourself. However, not getting enough alone time can affect you physically and emotionally. According to Dr. Marti Olsen Laney in her book The Introvert Advantage: How Quiet People Can Thrive in an Extrovert World, you may not be getting enough alone time if you regularly experience some of these symptoms:

  • Trouble sleeping or eating
  • Frequent colds, headaches, back pains, or allergies
  • Feeling anxious, agitated, irritable, and “snappish”
  • Unable to think, concentrate, or make decisions
  • Confused and discombobulated, as if you are dashing from thing to thing in a blur
  • Trapped and wondering what is the meaning of life
  • Drained, tired, and put-upon
  • Disconnected from yourself

What should you do? Make it a priority to include downtime in your day, even if it’s only 30 minutes of relaxing in your bedroom. Your introverted brain demands it! retina_favicon1

To learn more about the science behind introversion, check out my book, The Secret Lives of Introverts.


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