Often times, although we are attempting to hide our true feelings, our nonverbal behaviors reveal what we are thinking, even subconsciously. What is this called?

Body language.

Explanation:

If you see someone nervously wringing their hands, you can assume they're worried about something. If you see someone crying, the obvious assumption is to believe they are sad about something.

what do we need our phalanges for?

if this is true of false i think it would be true