What do you think reveals the most about a person without knowing much about them?

Hmm, a bit hard to answer this definitively. Humans are faceted and we can behave differently in every situation and environment. Everything we observe is merely a slice. Observing them when they have no audience or think no-one is watching, probably reveals the most in a short term sense. But then again, check out well known, well liked serial killers. Who knew.

Most things are tainted by our own perception, bias and many times projection me thinks.