Watch how people act when they’re not under the spotlight — when they’re in private or when they interact with someone who has no power over them.
This is the true indicator of a person’s character.
“And the most glorious exploits do not always furnish us with the clearest discoveries of virtue or vice in men; sometimes a matter of less moment, an expression or a jest, informs us better of their characters and inclinations, than the most famous sieges, the greatest armaments, or the bloodiest battles.” — Plutarch