Why do people grimace when they are exerting effort?

Asked by needaclue (122

) December 8th, 2008

I just opened a jar of peanut butter and I noticed my face was all squeezed up in a grimace as I applied torque. I often grimace when I’m exerting effort, like trying to stay upright on skis, or turning the mattress, or twisting beer caps. Other people do it, too. I call it face power, as if screwing up my face adds oomph! to the effort, but is there a physiological reason for it? Is there an evolutionary reason (see me be strong!)?

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3 Answers

Your face tenses up when your body tenses up. Your muscles are all interconnected. It would be far more odd to have a totally relaxed face while you were exerting effort.

bodyhead (5530

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I think that @body has it. What I also wonder is, why do some people stick out their tongue slightly when they are concentrating? Learned or genetic behavior?

steelmarket (3603

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