Social Engineering: The Art of Human Hacking

5.2. Microexpressions

You are probably familiar with the idea of reading facial expressions. When someone is happy, sad, angry, or whatever, when someone feels it you can look at his or her face and see that emotion. What if someone tries to fake that expression, like a fake smile? We have all done it, walking through the market and bumping into someone we just don't like that much—we put on a "smile" and say, "Hey John, nice to see you. Say hi to Sally."

We may act very pleasant and cordial, but inside we are feeling nothing but irritation. The expressions that we show for longer periods of time on our face are called macroexpressions and are generally easier for people to see the emotion that is being conveyed. Similar to microexpressions, macroexpressions are controlled by our emotions, but are not involuntary and often can be faked.

A certain few pioneers into the study of human behavior have spent decades researching something, coined microexpressions, to understand how humans relay emotions.

Microexpressions are expressions that are not easily controllable and occur in reaction to emotions. An emotion triggers certain muscular reactions in a face and those reactions cause certain expressions to appear. Many times these expressions last for as short as one-twenty-fifth of a second. Because they are involuntary muscular movements due to an emotional response, they are nearly impossible to control.

This definition is not a new understanding either; Charles Darwin wrote a book ...