Enlarge / Some people can raise goosebumps voluntarily, but how they do so is mysterious. (credit: Fuschia Foot / Flickr)

Imagine taking a popsicle stick and scraping it over your lower teeth. The feel of the wood’s texture might give you a case of the squirms, but for Susan Wilson, it’s a gateway to an unusual ability: thinking about it gives her goosebumps, on demand.

Eating popsicles as a young child, she says, “There was a little bit that always stuck on that wooden stick, and you’d scrape—” she breaks off with a mild yelp. “Ooooooh, it’s happening, right now while I’m talking to you. And then I realized as I got older that I just had to think about it and it would give the exact same—oh, I can’t get rid of them now—it would give the same response.”

Based on what we currently know about the body, this probably shouldn’t be possible: the muscles that pull on individual hairs to raise them, goosebump-style, are smooth muscles that aren’t under your control the same way your biceps or quadriceps are. But a paper published last week makes a cautious start on studying the phenomenon, exploring the experiences of 32 people like Wilson. The research found that people who can trigger their own goosebumps describe very similar sensations and triggers—and that the interplay between goosebumps and personality could give useful insights into how emotion works.