Academics often define introversion by what it is not: extroversion. What everyday introverts think about introversion is not really factored in.

As early as 1980, this problem was identified when a study found that the scientific and common-sense definitions of introversion were not the s...

Introverts tend to turn inward rather than outward, but beyond that, it is more complex. There are four types of introverts:

• Social. The preference for solitude or socializing with small groups instead of large ones. It is not the same as shyness.
• Th...