According to current research, if you were to make and hold the facial expression associated with surprise for about 10 seconds, your body would .

According to current research, if you were to make and hold the facial expression associated with surprise for about 10 seconds, your body would begin to produce arousal that would be unique to that emotion.

Explanation:

Studies by psychologists have shown that facial expressions have the (limited) power to affect one's mood. If a person smiles, which is a common expression of someone who is feeling happy, happiness can be elicited. Of course, if a person is going through a difficult moment, such as the loss of a relative, simply forcing a smile won't make that person stop mourning. Still, the studies prove that mood can be influenced by facial expressions.

A certain university study had participants obey to commands. They weren't told which feeling they were supposed to be triggering. They obeyed commands such as "raise your eyebrows" or "open your eyes wide." What researchers found is that participants ended up feeling what that expression was associated to. Therefore, if the researcher command facial expressions related to fear, participants would feel fear even though they weren't aware of the expression being one of fear.