Introverts, Extroverts and Science

Extroverts, Introverts, and the Brain’s Reward Center

As an introvert, I’ve always been intrigued (and at times annoyed) by the ability/propensity of extroverts to talk as much as they do, especially about themselves.  Before I really understood how extroverts were wired, I used to think they were unusually self-absorbed.  However, it is just that extroverts process information more externally, while introverts process internally.

Harboring a slight “holier than thou” attitude, I believed my silent thinking enabled me to more rapidly process information because I didn’t need to expend energy formulating sentences out loud.  I didn’t need to express my thoughts into words that could be understood by others, until they were well formed.  I could engage in processing silently while half-heartedly listening to my more extroverted colleagues and friends.

Before I go any further, for those of you who aren’t familiar with the concept of the introvert/extrovert continuum, it has nothing to do with shyness, loquaciousness, or being anti-social.  It is about the preference of extroverts to process externally and introverts to do so internally.

Most people understand that extroverts and introverts differ in how they get energized (engaging with people vs engaging with their internal world), how they experience external stimulation (“give me more please” vs “I need to limit it so I can think”) and the level of engagement with information and experience (breadth – lots of activities and friends’ vs depth – fewer friends and more intimacy).

We now know that the areas utilized in the brain are also different between extroverts and introverts.  Introverts have more blood flowing to multiple areas of their brains than extroverts, which makes sense when you consider that they are engaged in more internally focused processes (remembering, solving problems, and planning) as well as their thoughts and feelings about what they are processing. Think of a complex highway system of six lanes with multiple entrances and exits.

Extroverts, on the other hand, are processing external input, the visual, auditory, touch, and taste (excluding smell) sensory processes.  The neural pathways for this type of information are short and less complicated than that of introverts.  There are other differences between extroverts and introverts in terms of sensitivity to certain neurotransmitters and the hormone adrenaline.

Imagine my smug delight when I ran across an article in Scientific American in which scientists discovered that talking about oneself or self-disclosure is inherently pleasurable.  Researchers at Harvard, using functional magnetic resonance imaging (fMRI) discovered that talking about oneself is associated with the areas of the brain responsible for motivation and reward.

The “reward center” is part of the mesolimbic dopamine system.  When you enjoy a fabulous meal, respond immediately to the pings of your smart phone, or succumb to any addiction (drug, gambling, sex, alcohol, etc.), the reward center of your brain is activated.

Continued experiments indicated that talking about oneself, especially sharing information with another person about the self were additive.  In other words, doing both produced greater activation in the reward center of the brain.

“Ah-ha!” I thought to myself.  “No wonder extroverts like to talk about themselves so much!  They are lighting up their reward center.”  All of my smarmy delight was soon washed away in a flash-flood of realization as I continued to read the article.

The researchers discovered it didn’t matter if there was an audience for the self-disclosure!  Talking about the self is intrinsically rewarding, whether we are doing it externally or internally.  In other words, introverts like me, who spend a lot of time in self-reflection and introspection are also receiving a noticeable surge of activity in the reward center.

Although extroverts and introverts utilize different neural pathways to process information, and have different sensitivities to neurotransmitters, both get a “ticket to the reward center” when they speak or think about themselves.

Once again, my ego receives a come-uppance through science.  The more I learn about the brain and its seemingly magical abilities, the more my assumptions are crushed like fall acorns in my pet pig’s mouth.

Ya gotta love science!