If a crowded cocktail party feels like a holding cell to you, even as you gamely keep up your end of the chatter, chances are you're an introvert. Introverts are drained by social encounters and energized by solitary, often creative pursuits.
Extroverts make up about three-quarters of the American population, and as such come in all stripes. They zip through the world in search of novel experiences, social connections, and leadership opportunities.
Questions of personality have vexed mankind from the dawn of personhood: can people change? How do others perceive me? What is the difference between normal and pathological behavior? One's personality is so pervasive and all-important that it presents a clinical paradox of sorts: it is hard to assess our own personality, and impossible to overlook that of others.