But people aren’t skilled at spotting a phony guffaw, be it from a salesman trying to develop rapport with his client or from a student mustering support for a professor’s lame joke.
In one of Bryant’s studies, for instance, 37 percent of participants thought that a fake laugh – or what Bryant calls a volitional laugh – was real. Participants tended to be better at identifying natural laughs, in part because of a bias toward believing authenticity. Still, he said at an APA convention session on laughter, “there’s a difference in our ability to detect a real laugh versus a volitional laugh that’s not explained by a bias to think that things are real.”
So what’s the secret to spotting a laughing fraud? For one, authentic laughs tend to be higher pitched than forced chortles. “That probably has to do with greater arousal” among more authentic laughers, Bryant said.
Fake laughs also tend to be slower – “ha ha ha” versus “hahaha” – because they rely more our speech system, which isn’t so good at controlling “the opening and closing of the glottis,” Bryant said.
Finally, unnatural laughs tend to be noisier between each “ha” because, again, they’re more like speech. Real laughs are breathier — meaning that the next time you hear a real laugh, you may hear almost nothing at all.