In the above video, there's a fantastic example of a microexpression of fear. At the 0:55 mark - Zach Israel, a Barack Obama supporter who lost his seat at the President's DNC speech when it got moved indoors - displays a classic body language signal of fear on his mouth via a microexpression. While here, the "fear-mouth" is fully displayed, this extremely common nonverbal tell is often signaled more subtly and/or on just one side of the mouth during a deposition, negotiation or in a sales pitch.
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