I wrapped up reading my forth book of the year recently: Quiet, The Power of Introverts in a World That Can’t Stop Talking. The author investigated the contrast between extroverts and introverts and sighted several studies which showed the biological cause for these two general personality types.

One of the most interesting chapters focused on the Wall Street mortgage meltdown and how introverts and extroverts approached the situation.

According to the author, each personality type processes dopamine differently. Specifically how introverts and extroverts respond to the prosect of a reward. The author interviewed Dr. Janice Dorn, MD, pHD. Dorn explains that how our brain structure affects the relationship between risk and reward.

Our limbic system (old brain) includes the nucleus accumbens which is sometimes called the “pleasure center” of our brain. This part of our brain is telling us to take risks and “go for all the gusto that you can…and don’t think”. The limbic system also includes the amygdala which the book describes as the part of our brain that influences introversion.

Our “new brain” or the neocortex is that part of our brain which is responsible for reasoning, thinking, planning etc. It’s telling us to be careful, slow down, and think before we act. The old brain and new brain work together, but for extroverts the nucleus accumbens risk signals can tend to take over the reasoning ability of the neocortex. Here’s a quote from the book…

“But just as the amygdala of a high-reactive person is more sensitive than average to novelty, so do extroverts seem to be more susceptible than introverts to the reward-seeking cravings of the old brain. In fact, some scientists are starting to explore the idea that reward-sensitivity is not only an interesting feature of extroversion; it is what makes an extrovert an extrovert.”

The book is filled with studies and examples of how introverts and extroverts react differently to situations and more importantly WHY. I found the book really instructive for understanding my own reaction to situations as an introvert and how to deal with other personality types in a more effective manner. Understanding different personality types (including your own) can really help you to lead and communicate more effectively.

All in all it was a great read.