SPOT A PHONY
Your co-worker shakes his noggin almost imperceptibly while telling you he did not steal your idea and pass it off to the boss as his own. He so did.
As people big, split seconds of truth often flash across their face before their brain can retake control. Think of Mom's fleeting grimace before she says she really, really likes your new apartment.
Near constant hand-gestures like pointing, fidgeting, or face scratching, in someone who is usually relaxed can be a sign she is not being honest.
Liars take longer to answer questions than truth tellers and they may pause mid-sentence, making stuff up takes time.