Two important, misunderstood, terms. We extroverts (yes, I’m confessing) aren’t all loud, conversation hogs. Introverts-I count three among my closest friends-are not antisocial loners.

Yet, strong extroverts and strong introverts do differ noticeably from one another. They represent opposite poles of a continuum Carl Jung called Psychological Type. Extroversion and introversion persist in the human genome because each confers strengths that have supported human survival for a very long time.

Extroverts are energized by, and drawn to, the outside world. I, for example, love meeting new people and trying new things. I talk more than my introverted friends, and am seen as quick-witted. That, unfortunately, is because I don’t tend to do a lot of thinkin’ before I speak. In extroverted folk, the distance between the brain and the tongue is dangerously short. Too often, the cliche’ open mouth; insert foot (and ankle-and lower leg), applies perfectly.

Extroversion also yields a certain boldness. I rarely hesitate to take on a challenge that interests me, even if doing so involves swimming against the tide-e.g., leading as a lady in Ballroom Dancing.

I’m just not as sensibly cautious as my more introverted friends.

Extroverts also enjoy the spotlight. The life of the party is almost always going to be extroverted. Au contraire, you will hardly ever see an introvert wearing a goofy hat.

Introverted folk have a rich inner life that satisfies them, and are drained, rather than stimulated, by the outside world. Thus, they spend more time in the peace and privacy of their homes than extroverts. Innately risk-averse, introverts also prefer to scope activities, opportunities, and people out before engaging. Introverts talk less than extroverts because they consider their words carefully before speaking. Introverts are astute observers who catch details extroverts fail to notice. Introverts’ often have excellent analytical skills.

Unfortunately, the two species tend to misunderstand and judge one-another. Extroverts may write introverts off as boring. Introverts often perceive extroverts as boisterous and annoying. That’s too bad, really. Like other forms of prejudice, it’s rooted in ignorance.

Without extroverts, there would have been no long sea-voyages into uncharted waters, and no land expeditions into unexplored, dangerous, territory.

Without introverts, there would have been no one to say, wait a minute. There may be a safer route. I’ll figure it out.

Susan Caine’s book The Introvert Advantage presents an excellent overview of introverts’ and extroverts’ strengths. For a shorter primer, go here.