Introverts and extroverts The brain chemistry behind their differences - Introvert Whisperer

Introvert Whisperer / Introverts and extroverts The brain chemistry behind their differences - Introvert Whisperer Introverts and extroverts: The brain chemistry behind their differences Have you ever wondered why some people get excited by thrills and action while others find peace in reading a book, watching a movie or listening to music? Do you know what does it mean to be an introvert or an extrovert, and what makes them different? If you’ve, then you’re one of many because the debate over being an intro or extrovert has been going on for quite some time. Both of these terms are a type of personality and are known as the core traits of an individual. The difference  The terms ‘introverted’ an ‘extroverted’ were coined in the 1920s by Carl Jung, the noted psychologist. While he goes into the details of both these personalities in his journal Psychologische Typen or Psychological types, the main difference between the two is how they interact with the outside world and socialize. While extroverted people get a particular ‘high’ when they interact with others in a noisy environment, introverts often need to ‘recharge’ on their own after attending a party. According to stats, there are almost 50-74% of extroverts in the entire population who are also known as the ‘social butterflies’. On the other hand, the rest of the 16-50% consists of introverts who drive their energy from enjoying some ‘alone time’. Other than social interactions, introverts also take longer to decide, whereas extroverts are more likely to do and then think. Though there are a lot of tiny differences between these two personalities, it is good to remember that no one can be a complete introvert or extrovert. Everyone will have some characteristics of the other nature but will prefer one over the other. This article is going to explore the possible neurological and chemical reasons of why an individual becomes an introvert or an extrovert. However, you must bear in mind that though differences between the brain anatomies of both personalities have been noted, some external contributors, such as the type of people you were surrounded with when you were growing up, also matter. It’s all in the neurotransmitters    According to some research, it all boils down to dopamine, adrenaline, and acetylcholine, the three critical chemicals in our brain. Dopamine, the feel-good chemical, is responsible for your feeling of happiness, while adrenaline is the ‘spark’ that is ignited in situations which are dangerous or otherwise exciting. In the 1960s, Hans Eysenck, a renowned psychologist, believed that extroverts have a lower level of arousal. He theorized that extroverts have more receptors for dopamine in their brain as compared to introverts, and this is why they need more stimulation from the outside world to feel alert and active. On the other hand, introverts become over-stimulated in such a situation because they are sensitive to dopamine. This theory also helped explain why extroverts are often found taking risks and challenges and crave social interaction while introverts can find happiness in taking a stroll in the park. The Journal Frontiers in Human Neuroscience published a study in June 2013 that tested the reward centers of introverts and extroverts. The study, which was conducted by neurobiologists Yu Fu and Richard Depue, recruited 70 male freshmen from the Cornell University and put them through an introversion and extroversion personality test. Once the results were collected, the researchers did a double-blind where some of the subjects took Ritalin, a stimulant that boosts attention through the release of dopamine. Afterwards, all participants were asked to watch videos in a lab. Later, when extroverts where shown the video without taking Ritalin, it was found that just the video acted as a reward and motivation for the extroverts because they had associated the environment and context with the award. However, introverts showed no such association and the drug’s effect didn’t translate into any reward for them. On the other end of the spectrum is acetylcholine, which like dopamine is responsible for making you feel good; but the difference between the two chemicals is that while dopamine sets a ‘fire’, acetylcholine is subtle and makes you feel relaxed and content. In her book Quiet Kids: Help Your Introverted Child Succeed in an Extroverted world, Christine Fonseca explains that introverts prefer acetylcholine over dopamine. While dopamine loves excitement, thrill, outward interaction and the occasional jolt, acetylcholine is released when we turn inwards and engage in low-key and calming activities that are mentally engaging. As a result of this chemical being released in our body, we reflect, think deeply before making a decision and can focus on one thing for a long time. So, if you get brain power by writing or sketching, know that you are an introvert who is led by acetylcholine. The difference in neural pathways and system    Other than the variation in neurochemicals, science has also found a difference between the neural pathways and system of introverts and extroverts. Though there have been tons of research on this subject, one that stands out from the rest is the study conducted in 1999. During this study, conducted by Dr. Debra L. Johnson, researchers measured the cerebral blood flow of each personality with PET or positron emission tomography scans and found stark differences between the two. They found that while the extrovert’s blood flow went through the cingulate gyrus, temporal loves, and posterior thalamus, the introverts experienced more blood flow in their frontal lobes and anterior thalamus, both of which are responsible for problem-solving and memory. These findings are in line with why extroverts are more outwards focused while introverts pay more attention to what they feel inside. Another difference uncovered by Dr. Marti Olsen Laney has to do with the nervous systems of the two personalities. While all our nervous systems have two sides; the sympathetic side and the parasympathetic side, it was observed that extroverts mostly use their sympathetic side. This side, which is also known as the ‘fight, fright or flight’ mode, is activated when your body gets ready for action and dopamine increases at the back of your brain. On the contrary, introverts use their parasympathetic side which is also called the ‘rest and digest’ mode. While the body gets activated through the sympathetic side, the parasympathetic relaxes your muscles, restores your energy and metabolizes your food. Unlike releasing dopamine as is right with the sympathetic side, acetylcholine is released which relaxes you and makes you alert. Other alterations    Dr. Marti Olsen also says that genes may be responsible for the introverted and extroverted personalities in her book The Introvert Advantage. According to her findings, a great deal of research has been done on the D4DR gene, which is known for novelty seeking. In her book, she says that even though no one gene can decide a temperament, the D4DR, which is on the 11th chromosome, is seen to be longer in extroverts than in introverts. Finally, a study conducted by Randy Buckner of Harvard in 2012 discovered that introverts tend to have larger and thicker gray matter in their prefrontal cortex. The prefrontal cortex, which is associated with abstract thought and decision making, doesn’t have as much gray matter in extroverts. The scientist concluded that this might be the reason why introverts relish reading an excellent and thoughtful book that boosts their mental cognition and keeps them fit. The takeaway    The human brain is one of the most complex parts of the body and though a lot of research has been done on extroverts and introverts, a lot more need to be conducted to understand what sets these two personalities apart. For now, the plethora of information that is present is enough to suggest that whether introvert or extrovert, it is essential that you focus on your brain health and give it challenges so it can become stronger. AUTHOR BIO ABOUT Alycia Gordan