Deception Detection, What Does It Mean When Someone Breaks Out in a Sweat?

Uncover Deception.
When you know details of a transgression that the suspect does not know you now look at their nonverbal response when you reveal details to them. An Innocent person would not get nervous when details about something they didn't do are revealed. Below is a powerful story from a workshop participant who saw this work. My guess, in the story described, is that the suspected thief had prepared for the big questions but when the questioner knew small specific details it tended to make the guilty person feel more exposed and nervous.

I was in a deception detection session with you this past summer. In October I went to a European country, I won't name, to look into allegations that our ---- was stealing from us. I took part in complicated interviews with the subject and our accountants that were largely conducted in his language because neither the ---our accountants were fluent enough in English to deal with such a stressful situation and get the meaning right. So my U.S. colleague and I were dependent on our watching skills more than our listening skills. At first I was unable to sense any change in tone, speed, or bodily position as the --- lied to us for about an hour. That is, until we got to questions where we had details. When the accountant started that line of questions, the --- broke out into a sweat that was visible on his face. Your speech helped me recognize the change. You said knowing details even seemingly small ones helps. And sure enough the details were part of a fairly minor transgression compared to the real theft!), I knew enough not to let go of that issue until we had proof that he had committed a crime.

Thanks for speaking to us. I had no idea I would be putting what I’d learned to use so quickly.

Patti Wood, MA, Certified Speaking Professional - The Body Language Expert. For more body language insights go to her website at Also check out the body language quiz on her YouTube Channel at