Nature and Nurture

Are these traits born or built? Twin studies give a clean answer: roughly half genetic, half environmental. You arrive with leanings, then life turns the volume up or down.

Two things follow. First, your baseline isn't a moral failing. Judging yourself for it makes as much sense as judging your height. Self-acceptance starts with knowing your tendencies are partly hardwired.

Second, the dials still move. An introvert won't morph into a party host, but can get comfortable in a crowd. Most people drift more conscientious, more agreeable, and calmer with age.