Would I lie to you? (Engineering trust with your face)

Spurred by the ever-more-bizarre case of impostor Clark Rockefeller, the Boston Globe featured a very interesting story on Aug. 17 on how con-men engineer trust.

The article talks about how mimicking the speaker’s movements creates trust (even when the speaker is unaware of this mimicking), how minutely small bonds between individuals (like claiming that you used the same amount of paint in a recent paint job) makes one’s recommendations in a paint store be taken more seriously, and how MIT-researchers have been able to use sociometers (measuring the intonation of one’s voice, distance away, which way one was facing, etc.) to be able to predict which business pitches people would find persuasive or not.

Some of the most interesting research is on facial features (which brings to mind a very interesting story a while back by Malcolm Gladwell called “The Naked Face“).

Author Bennett notes that things as small as the slope of the eyebrow or the thickness of the chin send signals about whether they are to be trusted. “According to recent work by Nikolaas Oosterhof and Alexander Todorov of Princeton’s psychology department, we form our first opinions of someone’s trustworthiness through a quick physiognomic snapshot. By studying people’s reactions to a range of artificially-generated faces, Oosterhof and Todorov were able to identify a set of features that seemed to engender trust. Working from those findings, they were able to create a continuum: faces with high inner eyebrows and pronounced cheekbones struck people as trustworthy, faces with low inner eyebrows and shallow cheekbones untrustworthy.

“In a paper published in June, they suggested that our unconscious bias is a byproduct of more adaptive instincts: the features that make a face strike us as trustworthy, if exaggerated, make a face look happy – with arching inner eyebrows and upturned mouths – and an exaggerated untrustworthy face looks angry – with a furrowed brow and frown. In this argument, people with trustworthy faces simply have, by the luck of the genetic draw, faces that look a little more cheerful to us.

“Just as in other cognitive shorthands, we make these judgments quickly and unconsciously – and as a result, Oosterhof and Todorov point out, we can severely and immediately misjudge people. In reality, of course, cheekbone shape and eyebrow arc have no relationship with honesty.”

It appears that for evolutionary purposes, it was important to be able to make relatively rapid judgments of whom could be trusted. It seems weird that over millennia, genes wouldn’t have had a hereditary advantage that came up with better heuristics for assessing trust than this one commonly used (if it had no relationship with honesty). Then again, it may be that facial expressions in concert with other signals from the speaker (tone, style, affect, excitement, sweat, etc.) were actually relatively good proxies for truth-telling. For sure those who weren’t very good at judging who was going to stab them in the back, generally didn’t live long enough to be able to pass on their genes.

Read the whole interesting article “Confidence Game” (Boston Globe, 8/17/08 by Drake Bennett)

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