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.

Uncharted territory

James Heathers, the lead author on the paper, stumbled on the idea of voluntary skin prickling when it was referred to off-hand in something he was reading. “I couldn’t get it out of my head,” he says.

After diving down a few rabbit holes, he emerged knowing two things. One, voluntary goosebumps had been reported in enough different places that they were probably real. And two, nobody had bothered to study this in any great depth: “Three case studies in about 100 years! That’s not a lot of research interest.”

So, he did what we all do when we want to find people who experience strange phenomena: he went looking for groups on the Internet. “There were little pockets of people... all over the place,” he said, and he teamed up with a group of other researchers to recruit the first-ever study on “voluntarily generated piloerection”: VGP.

One of the questions Heathers' team asked participants was to just describe what their experience felt like. “These open-field responses overwhelmingly described a process which was physical and reflex-like, rather than an exercise of the imagination or re-experiencing,” Heathers and colleagues write in their paper.

“I tighten a muscle behind my ears... and the goosebumps appear on my back and then travel to my arms,” writes one participant. “I think about goosebumps, they start to appear, I shudder/shiver, and there they are,” writes another. A few people, like Wilson, imagine a goosebump-inducing experience. But most of the participants can just consciously trigger the sensation at the back of their head or neck.

Wilson’s also unusual in not enjoying the experience. “I’m freezing now,” she tells me, after several minutes spent describing her experiences has left her with continuous goosebumps. “It’s such a strong reaction. And I can’t get my head out of the loop.” For most of the people in the study, though, it’s a pleasurable experience. Many people say they give themselves goosebumps when they’re listening to music, meditating, or even having sex—and that they use their ability to prolong any involuntary goosebumps they experience.

The goosebump mystery

Goosebumps themselves are pretty weird—at least, the way humans experience them. When other animals get goosebumps, it’s because they’re cold or angry. But humans, strangely, get them when we listen to “Nessun Dorma” or gaze at Vincent van Gogh’s Sunflowers. Those don’t seem to be remotely related to cold or anger, as Heathers points out: “No-one’s ever seen Sunflowers and gone, ‘Right, that’s it, we’re going to throw down, Van Gogh! I’m going to fuck you up.’”

Instead, the participants’ experience of goosebumps sounded somewhat similar to that of people who experience Autonomous Sensory Meridian Response (ASMR), a pleasant tingling sensation that starts on the head or neck in response to certain kinds of sights and sounds. People who experience ASMR have been found to score higher than average on a personality dimension called openness to experience. So have people who get more involuntary goosebumps. Because of this, Heathers and his colleagues wanted to see whether their VGP participants also scored higher on this trait.

As expected, they found higher openness to experience, but it’s not a result the researchers are taking too seriously just yet. Heathers points out that people who participated in the study are likely to have explored their bodies long enough that they’ve figured out they are capable of an atypical thing and are now out on the Internet trying to learn more about it.

“Am I preferentially recruiting open people because they’re the ones that I’m more likely to find?” Heathers wonders. “Or is it a correlate of the experience itself?”

VGP IRL

Ideally, what you want is to get people in a lab, giving themselves goosebumps in front of scientists’ raised eyebrows and dropped jaws.

“I want to put probes on people!” Heathers exclaims. “I want to take measurements; I want to see how it works.”

For this paper, he and his team screened hundreds of undergrads, trying to find even a handful of people. But no one passed the screening—which does at least give them some information about how rare the ability is.

“I think that this next step is essential,” says Stephen Smith, who studies ASMR. Finding people in the (bumpy) flesh would also allow the researchers to confirm that the people do definitely have VGP. “Without testing the people in person, it is difficult to say if they actually had VGP or some other condition,” Smith adds. “I think we need to be cautious about interpreting results that are based on Internet samples.”

The VGP researchers are already banging the caution drum. “You can’t just do a single study then claim to know everything,” writes Heathers on the Facebook page he uses for recruitment.

At this stage, there are far more questions than answers. But Smith is enthusiastic about the way this paper will start to open up the field: “I’m sure that this paper will lead to increased research into this interesting condition.”

Wilson, who got in touch with Heathers after finding out about the initial survey, is eager to discover what’s going on in her own body. Her background in electrical engineering gives her a particular lens on human brains acting in unexpected ways: “When I think about trying to wire billions and billions of these neurons—well, of course there’s going to be some cross-talk or some wrong wiring. I’m surprised that we all walk around as normal as we do.”

If you can give yourself goosebumps, Heathers would like to hear from you: email him at j.heathers@northeastern.edu.

PeerJ, 2018. DOI: 10.7717/peerj.5292 (About DOIs).