The Zombie Science of Bad Dancing

An undead news item takes another turn around the floor.

Two men dancing.

Two men evaluate each other’s right knees.

Photo by Ryan McVay/Thinkstock

What makes men attractive on the dance floor? A video posted on Slate last Monday, among the site’s most popular for the week, promised a scientific answer. For a study conducted at Northumbria University in England, psychologists brought young men into the lab and motion-tracked their dance moves as they grooved to a 30-second drumbeat. Then they turned the data into 3-D animations and played the movies back for a set of 37 women who rated them for “dance quality.” Here’s the take-home finding, as determined by the academic experts: If you want to dazzle in the club, the video declares, just “bend and twist your right knee faster.”

That sounded odd to me, and implausible. (Your right knee, seriously?) It also seemed familiar. Sure enough, when I clicked the link to the original research paper, I found that it was published in early autumn 2010. Lots of coverage followed at the time—from the AP, from ABC, from the BBC, from NPR, from NPR again, and from many other outlets. And so, just four years, four months, and three weeks before the recent video was posted, that Northumbria psychologist and lead author Nick Neave had the chance to tell the world that “the speed of the right knee movements [is] very important” for dudes who like to dance.

But Neave’s sexy knee had all but disappeared a few days later—or, really, it was buried in the dirt of forgotten research findings. The same scientists put out a pair of follow-ups in 2011, both on the subject of how women perceive male dancers, and both using the same motion-tracking system as the first, but neither got a whiff of interest from the press. In early 2013 a fourth study in the series, “Male body movements as possible cues to physical strength,” received some mentions, including in the Daily Mail and the BBC. Then it, too, blew into the breeze.

By that time, the original research—Neave’s small, preliminary study on “Male dance movies that catch a woman’s eye”—was already more than 2 years old, and seemingly irrelevant. Subsequent experiments had superseded it, and in some ways contradicted its results. Yet that 2010 paper was the one that reappeared last week, freshly disinterred from the graveyard of academic publishing. A piece of zombie science seemed to walk among the living.

I was curious why this happened, so I started tracing back in time. Who, exactly, reanimated this dead research, and how did it come to shamble onto Slate? The first step, going backward from the present, was Business Insider, where a young producer named Justin Gmoser had made a piece titled “Scientists Discovered What Makes Someone a Good Dancer.” His two-minute video was posted on BI on Jan. 24, two days before it made its way to Slate via a content-sharing partnership. I called Gmoser up and asked him what inspired him to cover a story from 2010 in 2015. “This was actually reposted,” he said. The video first went up last spring, then ran again on Sept. 20, and once more on Oct. 4.

So Business Insider posted Gmoser’s video four times during a 10-month span, and the piece was shared on social media at least half a million times. But why did Gmoser make the video in the first place, several years after the original research? “One of my editors sent me a story from the Daily Mail,” he said.

I traced another path of media contagion that started when Gmoser’s video made its way into the news feed of a tech entrepreneur named Samir Varma, who dug up the original research paper and tweeted it on March 20 of last year as a “good read.” Tyler Cowen, of the well-respected economics blog Marginal Revolution, picked up the story from Varma, and put up a link to the 2010 research paper, with no mention of its publication date.

Cowen’s blog ended up in front of Christopher Ingraham, a data journalist at the Washington Post, who wrote up the research once again. (The Post used his story twice, in fact, in both March and November of last year.) Now bearing the imprimatur of a top newspaper, the 4-year-old dancing study could take another turn. “The Washington Post looks at a study of what women want on the dance floor,” said Gayle King of CBS This Morning, when she introduced the story on March 25.

Other versions spread to outlets from across the globe, but the first citation that I could find in this revival was indeed the story in the Daily Mail. Its Dr. Frankenstein turned out to be a science editor named Vicky Woollaston (not quite Wollstonecraft, but still!), who wrote up the study on March 17. (The Mail would reprint her work with a snazzier headline on March 30.) That’s where the trail ran cold: Woollaston couldn’t say why she chose to re-report a piece that had been written by a different Mail reporter back in 2010. “I don’t remember specifically,” she told me via email, “but it may be that the video was trending somewhere.” Which video, and trending where? I found nothing to support this conjecture. No outlet showed much interest in the out-of-date research until the day or two after Woollaston’s article came out.

Even Neave, the study’s lead author, was surprised by the article’s resurgence. The Daily Mail did not reach out to him for comment, at least not in 2014, so he had no idea the coverage was coming: “Suddenly our press agent contacted me and said, ‘Nick, there’s people from all over the world ringing in again about the dance stuff!’ ” On April 1 another story on the same experiment showed up in Neave’s local newspaper, phrased in the present perfect tense, as if the work had recently been carried out. The paper’s offices in Newcastle are just a 15-minute walk from his laboratory.

Does any of this really matter? I’ve observed the phenomenon before: Certain science stories seem to come out like cicadas, swarming the Internet for a month or two before retreating underground for several years until the next cycle of coverage begins. A few weeks ago, for example, This American Life ran a story, “Batman,” on the miracle of human echolocation. The same miracle received a lot of press in early 2011, when the same echolocating blind person, Daniel Kish, participated in a study using fMRI. And that was just five years after People ran a spread on “The Boy Who Sees With Sound,” a five-minute celebrity who taught himself to echolocate like Daniel Kish. It should be said that Kish did not invent human echolocation: The skill is well-known to those in the blind community, and has been “discovered” many times by scientists.

Most research gets one chance at being covered in the press, at the moment of its publication in a peer-reviewed journal and the distribution of an accompanying press release. But certain studies—like this one from 2006, on the physics of tangled headphone wires—can be reheated and rehashed as if no time has passed. That’s not so bad, in principle: If a study tells us something useful or amazing, why not dust it off from time to time? We all should strive to spread the wealth of human understanding, whether it’s to do with human-powered sonar or the mysteries of knots.

In practice, though, the sort of science that comes back from the dead—the truly necromantic stuff that tends to show up first in Britain—isn’t good; it’s grabby. A zombie research story doesn’t care for scientific truth; its only mission is to gobble up your clicks. It doesn’t even have to be that interesting, so long as it can sustain a certain rate of reproduction—an R0 sufficient for its viral spread.

That’s how we ended in this stupid mess where the “secret of male dancing” has formed a zombie-science army and marched across the Internet. That topic may have wide appeal, but the study simply isn’t valid. It makes the prima facie silly claim that good dancers are the ones who bend and twist their right knees. What’s the evidence for that? Neave and colleagues found a correlation between kinematic measures of that body part and the subjective ratings of their female subjects. Take a look at the data, though, and you’ll see they measured three movement variables—amplitude, variability, and speed—across 36 joints and motions, ranging from flexion of the right shoulder to external rotation of the left ankle. In all, they were prepared to test for 108 separate correlations, and then claim significance for any that might have turned up 1 in 20 times by chance.

You don’t need to be a statistician to be suspicious of this approach. Sure, the right knee might be the secret of male dancing, but it could also be a product of the study’s paltry sample size (just 19 dancers) and its overworked analysis. Neave trumpeted that finding anyway, back in 2010. The sexy-knee effect remains the highlight of the work in all the zombie coverage that began last year. But when I talked to Neave this week, he admitted that the right knee may not be so special after all. “It was a bit odd, about the knee,” he told me. “When we ran the study with more participants, that variable disappeared.”

In fact, more recent work from Neave and colleagues has turned up several other contradictions. The group’s 2013 study, for example, found that large and rapid arm movements, not those of the trunk and knee, were the key to attractive dancing. The very same variables had shown no predictive value whatsoever in the original study from 2010. Another study, from 2011, found that the best male dancers tend to be the ones who are most prone to thrill-seeking behavior, but a follow-up turned up the somewhat discordant fact that sexy dancers are also very conscientious and socially agreeable.

Naturally, the evolutionary psychologists behind this research can explain any strange results. Arm movements matter more in sexy dancing, they say, because women key in on male upper-body strength as a sign of reproductive fitness—you know, fist-fighting over mates and all that. But a few years ago, Neave suggested that the right knee might be important to dancing because men evolved to be “right-footed.” We’re also told the same upper-body theory explains the fact that good dancing correlates with handgrip strength (which signals upper-body brawn) but not jumping ability or endurance.

Then again, we also know—or think we know—that hand-grip strength correlates with body symmetry, which is itself a marker of reproductive fitness. And what’s more, a study published in Nature in 2005 found that body symmetry correlates with sexy dancing! “That was a fascinating study,” Neave told me. “It looked to be really, really powerful. That was a major impetus for us to do our [dancing] research.”

As it happens, that 2005 Nature study—the best-known in this tiny subfield of psychology—was retracted in 2013, at the behest of its senior author, Robert Trivers. (He now alleges that a postdoc faked the data.) I asked Neave if his group has checked for a symmetry effect, and he said they’re waiting for more data. “We don’t feel that we’ve got sufficient numbers,” he told me. “You’d need 200 men to find any clear association with that stuff. There’s so much noise.”

But what about the other associations that your group reported? I asked. Why should the relationship between a man’s dancing and his personality, or between his dancing and his upper-body strength, be any less noisy that the one between his dancing and his symmetry? Why would you need 200 men for one analysis but just 19 for all the others?

Neave acknowledged some uncertainty. “I’m not saying that we have the answer to anything,” he said. “Science progresses by people making mistakes, and then other people coming along and doing things better, and we all benefit from that.”

So true: Scientists will make mistakes, and science buries them in further findings. It’s a sensible routine, and one that has been in play for centuries. The problem comes not from guys like Neave, well-meaning if at times misguided, but from the grave robbers who dig up decrepit studies just to steal some traffic. When we don’t stop to read the warnings in the literature, we unleash a mummy’s curse on science journalism. Once the zombie plague gets going, it’s hard to stamp it out.