Attractiveness studies are hot, or not

Good-looking people seem to get all the breaks. They have the leg up on getting a date, a job, a leading role. You’d think that would be enough, but no. We, the public at large, apparently want to give them more.

We want to bestow the attractive with all kinds of special powers. Take a couple of recent media reports on new studies. “Slim, Attractive Men Less Likely to Have Bacteria in Their Noses,” one headline announced. And in a blog post at Discover magazine: “Science has just shown one more benefit to being really, really, ridiculously good looking: riding a bike faster. No, really.”

Well, not really. The bike-riding study in question did look at the relationship between attractiveness ratings of Tour de France cyclists and their racing performance. But not only should the results be interpreted with caution for various statistical reasons (stay tuned), some of the news coverage of both the Tour de France and nose bacteria studies has really stretched the interpretation of cause and effect. In other words, certain traits might make someone more likely to be attractive to others, but that doesn’t necessarily mean that attractive people are more likely to have those traits.

Sure, there are reasons why attractiveness might correlate with cycling performance or even germiness. Women are more attracted to physically fit men, for example, and more physically fit men probably perform better in the Tour de France. Overweight men, on the other hand, might be both less attractive to women and be prone to some health problems that affect their nasal bacteria. But none of this means that attractive men have the market cornered on cycling skills or clean noses.

“The data certainly don't warrant such breathless conclusions as reported in the media,” says statistician Regina Nuzzo of Gallaudet University in Washington, D.C. “The real picture is much more complicated.”

In the Tour de France study, researcher Erik Postma of the University of Zurich had 816 men and women rate the attractiveness of photos of riders who finished the race in 2012. “I show that riders that performed better were more attractive,” Postma writes February 5 in Biology Letters. In this case performance was a weighted average of the rider’s times on various trials, a very specific measure that Postma intended as a measure of endurance. It’s impossible to know from this study alone whether the findings would hold up using a different measure, Nuzzo notes.

Plus, you have to put the study’s main finding in perspective, Nuzzo says. The riders’ performance factor accounted for only 5.5 percent of the variability in their attractiveness scores, meaning that most of their attractiveness score was accounted for by other factors, such as height, weight and other differences among riders.

Even more surprising was a February study in the American Journal of Human Biology that seems to link attractiveness to nose bacteria. Researchers in Poland dug into the noses of 103 women and 90 men looking for six species of bacteria that can make people sick. Then they related the presence or absence of these bacteria to certain body measurements. No one actually rated how attractive each volunteer was. Instead, the researchers used the volunteers’ self-reported height and weight (combined as body mass index, or BMI), plus measurements of the women’s waist-to-hip ratios, as a measure of attractiveness. A normal-range BMI (neither underweight or overweight) is usually rated as more attractive in both men and women, as is a smaller waist-to-hip ratio in women, which gives an hourglass shape with a smaller waist than hips.

The researchers’ hypothesis was that more attractive people would carry fewer nose germs. Body measurements that affect attractiveness are “honest signals of biological quality,” they argue, so “people with more attractive values of these traits should be more immunologically competent.” In other words, attractive people are also healthier people, who should have better immune systems that fight off nasal pathogens.

But the results were different for men and women. Women in the study with the more attractive low waist-to-hip ratios were actually more likely to be colonized by pathogens. But men whose noses were colonized by the pathogens had higher BMI values on average, and that’s the result that was promoted in a press release and ultimately drew media attention.

It’s an interesting idea, worth exploring in the context of how accurately humans can discern the health of others. It makes sense that we’ve evolved to pick up on and be attracted to good health, which might translate to more and healthier offspring. But can we really say that attractive men have less germy noses?   

That’s a stretch. “You can't flag just one positive finding (men's weight) and leave out the finding that contradicted their original hypothesis (women),” Nuzzo says. Apart from the uncertainty of relying largely on self-reported measurements, she points out, the authors double-dip their data by testing height and weight separately and then again as body mass index, or BMI, which combines height and weight. Not to mention that BMI is not always a good indicator of attractiveness in men: Very muscular men can have higher BMI than flabbier men. Shoulder-to-hip ratio would be a good measure to look at in addition to BMI, but it wasn’t used in the study.

My point here isn’t to dismiss these studies, or research on attractiveness, out of hand. Both studies tested interesting ideas, but news headlines like “Gorgeous men have less nasal bacteria!” don’t do justice to the actual science. I think we all, men and women, have enough hang-ups about our looks already without worrying whether our nose bacteria mean we’re attractive or not, thank you.