DEAD GIVEAWAYS

What’s written all over your face?

Whether it’s Pinocchio’s nose, poker tells or fictional detectives who solve  a crime after being tipped off by the flicker of someone’s eyebrow, much has been made of the messages written across our faces. They are the vulnerable spots that we alone can’t see, but which can broadcast our feelings to those around us. In reality, people can’t be read as easily as popular culture would have us believe. “No verbal or non-verbal behaviours will be Pinocchio’s nose,” says Leanne ten Brinke of the University of California, Berkeley, who studies body language. Instead, we should look for collections of cues. People often find it easier to fake positive emotions than negative  ones, because they involve only  two muscles: the zygomaticus major, which helps curl the mouth when we smile, and the orbicularis oculi that crinkles the skin around the eyes into crow’s feet. If you want to catch someone out, better to look for crocodile tears. In a landmark study last year, ten Brinke and her team asked volunteers to tell two stories: one about an incident they regretted, and one about an incident they didn’t. Then they were told to convincingly pretend to regret the latter. Their disingenuous expressions yielded a treasure trove of tells. “Facial muscles that should have been engaged were suspiciously absent,” says ten Brinke. Looking sad involves the contraction of complex, involuntary muscles in the forehead. Such movements proved too challenging for the subjects,  and their efforts appeared closer to cartoonish surprise than sadness. Conversely, facial muscles that should not have been engaged were. This “emotional leakage”, as ten Brinke calls it, tripped up all of the participants at least once (Law and Human Behavior, vol 36, p 51). Emotional leakage occurs either when the liar becomes distracted  by gleeful feelings of getting away with their deceit, or embarrassed  at being unconvincing. Both come across like a smirk, she says. It is hard to maintain emotional consistency throughout a faked sob story. Liars’ faces are emotionally turbulent, swinging between positive and negative expressions, found ten Brinke, in marked contrast to the neutrality often displayed by someone telling the truth. If all else fails, look to the eyes, says Mariska Kret at the University of Amsterdam in the Netherlands. “When you lie, your pupils dilate,” she says. And with good reason. Although it has long been known that pupils dilate when we are sexually aroused, Kret’s research shows that they also expand under emotionally extreme conditions such as anger or fear. Unless you are a psychopath,  she says, “lying is not something you do without feeling a bit stressed”.  As with any cue, though, it’s all about context. Pupils dilate in many situations, so it would be risky to assume someone is lying based on their eyes alone, Kret says. But combined with other cues, it could suggest someone is afraid or angry that the game is up.  ■