We generally think of extroverts as people who are outgoing, confident, loud, and sometimes over-bearing; and introverts as quiet people who lack confidence and are anti-social. When we’re trying to figure out if someone is an extrovert or introvert, we tend to judge them against these criteria, and whilst some individuals seem to match these stereotypes perfectly, most fit neither box exclusively.
That’s probably because we’re using the incorrect yardstick. Carl Jung, well-known psychiatrist and psychoanalyst, was the first to create the concept of extroversion and introversion in the early 1900’s. He defined these traits based on our energy source to recharge. Introverts recharge through being alone, whilst extroverts gain energy from other people and through social interactions. Jung said, “Each person seems to be energized more by either the external world (extroversion) or the internal world (introversion).” Our brains are wired differently, and therefore, react differently to stimulation. Extroverts have a lower basic rate of arousal, so they need more stimulus than introverts, who are more sensitive to external stimulus and therefore can find the same level overwhelming and draining.