UK researchers found that people responded to genuine smiles in less than 200 milliseconds (the fastest we can process an expression and respond with a voluntary one) more often than when their partner put on a polite grin. Although the researchers classified any smile involving the eye muscles as genuine during analysis of 48 videotaped one-on-one conversations between adults of the same sex, the real markers are internal. “There’s an emotional component to it that feels very different than a polite smile, a feeling of positivity,” says study coauthor Erin Heerey, PhD, senior lecturer in the school of psychology at Bangor University. If you dish out a genuine one, you have pretty good odds of getting one back. In 619 total smile exchanges during the 48 interactions, smile types were matched more than 92% of the time, a stat backed up by previous research on the topic. On the flipside, it’s unlikely that a half-hearted grin will drum up an enthusiastic response. Because no matter how good your stock grin is, that split-second time lag could be a clue to others that it’s not spontaneous. “If you give a genuine smile, you will predict that feedback is going to occur within 200 milliseconds,” Heerey says. “If my smile doesn’t occur for a full second, you’re going to be disappointed, and probably not consciously.” Still, smiling because you have to won’t necessarily sabotage a social interaction. People see polite smiles as more positive than neutral expressions—if you’re both on the same wavelength. “Failure to match on smile type makes interactions feel really awkward,” Heerey says. So smile like you mean it—you’ll leave others wondering why they can’t help but do the same when you’re around. More from Prevention: Love Your Smile
