Scientists: Maybe Yawning Isn’t Contagious After All

iStock
iStock

Everyone knows that yawning is contagious. What this new study presupposes is … maybe it isn’t? The report was published in the journal Adaptive Human Behavior and Physiology.

Anecdotal evidence—that is, our own lives—certainly suggests that the act of yawning spreads. Many studies have documented the phenomenon as well. And humans aren’t the only ones; we've seen rats, chimpanzees, dogs, and even parakeets pass yawns to each other.

But have we really proven it? Rohan Kapitány of the University of Oxford says no. The experimental psychologist conducted a review of the scientific literature on contagious yawns and found very little conclusive evidence to back up our assumption.

“The belief that yawns are contagious seems self-evident,” Kapitány told PsyPost, “but there are some very basic reasons for why we might be mistaken in this. If we fail to dissect that which we think we know, we might end up with conclusions that do not reflect reality. In this instance, the literature hasn’t questioned the basic features of contagious yawning, and ended up with a wide range of unstandardised methodologies and conclusions.”

So Kapitány and his colleague Mark Nielsen designed an experiment to put those conclusions to the test. They recruited 79 college students—psychologists’ favorite guinea pigs—and broke them into small groups. Each group sat around a table together, wearing headphones that played Chopin’s Complete Nocturnes. Some of the participants were blindfolded, and some were not. The sessions were videotaped.

Afterward, the researchers calculated the number of times each person yawned, and when, and whether they did so after seeing somebody else do it.

On their surface, the initial results supported the contagious-yawn concept. The longer the participants sat in the room together, the more they yawned, especially if they could see other people.

But things got murkier once the researchers dug deeper into the data. Their findings suggested that one person’s yawn could not reliably make another person yawn within 3 minutes. Everybody yawned, but there didn’t seem to be a causal relationship between one person’s yawn and another’s.

This study was small and extremely limited, and the authors urge other scientists to challenge their findings with experiments of their own.

“I may be wrong!” Kapitány said. “Maybe yawns are contagious!" Kapitány says he’d like to see “more robust” attempts to falsify the claim that yawns are contagious rather than “simply demonstrating it over and over [in] slightly different contexts with richer and richer explanations.”

NOTE: We used the word “yawn” 17 times in this article. We’re yawning now. We bet you are, too. More research is definitely needed.

[h/t PsyPost]

Bombshell, Victoria’s Secret’s Bestselling Fragrance, Also Happens to Repel Mosquitoes

Dids, Pexels
Dids, Pexels

People love Bombshell, the best-selling fragrance at Victoria’s Secret, for its summery blend of fruity and floral notes. Not everyone is a huge fan, though: As Quartz reports, the perfume is surprisingly good at warding off mosquitoes. In fact, it’s almost as effective as DEET insect repellent, according to the results of a 2014 experiment by researchers at New Mexico State University.

Researchers took 10 products that are commercially available and tested their ability to repel two different species of mosquitoes: the yellow fever mosquito (Aedes aegypti) and the Asian tiger mosquito (Aedes albopictus), both of which are known to transmit diseases like dengue fever, chikungunya, and yellow fever. In doing so, volunteers subjected their own flesh to the test by placing their hands on either side of a Y-shaped tube containing the blood-sucking critters. One hand was covered in a synthetic rubber glove, while the other hand was sprayed with one of the products but otherwise left bare. Researchers recorded which tunnel the mosquitoes flew to, and how long they avoided the other end.

Three of the products contained DEET, while four products didn’t. In addition, there were two fragrances (including Bombshell) and one vitamin B1 skin patch. The DEET products were the most effective, but Bombshell proved to be nearly as good, keeping mosquitoes at bay for roughly two hours.

“There was some previous literature that said fruity, floral scents attracted mosquitoes, and to not wear those,” Stacy Rodriquez, one of the study’s authors, said in a statement. “It was interesting to see that the mosquitoes weren’t actually attracted to the person that was wearing the Victoria’s Secret perfume—they were repelled by it.”

This isn’t the first time a perfume has had an unintended effect on the natural world. It turns out that tigers are obsessed with Calvin Klein’s Obsession for Men cologne, partly because it contains a synthetic version of civetone, a pheromone that's secreted by glands located near a civet’s anus. This substance was once used to create musky fragrances, but nowadays the scent is mostly reproduced in a lab. Still, the fake stuff must be pretty convincing, because big cats go crazy when they catch a whiff of it.

[h/t Quartz]

Mystery Solved: Scientists Have Figured Out Why Some Squirrels Are Black

Rena-Marie/iStock via Getty Images
Rena-Marie/iStock via Getty Images

It can be something of a surprise to see an animal sporting a fresh coat of paint. Blue lobsters occasionally surface after being caught in traps. A pink dolphin was spotted in Louisiana in 2007 (and several times since). In the Chinese province of Shaanxi, a cute brown and white panda greets zoo visitors.

Another anomalous animal has joined their ranks. Black squirrels have been spotted in both the United States and the UK, and now scientists believe they know why.

Like many animals with unusual color schemes, black squirrels are the result of a genetic detour. Researchers at Anglia Ruskin University, Cambridge University, and the Virginia Museum of Natural History collaborated on a project that tested squirrel DNA. Their findings, which were published in BMC Evolutionary Biology, demonstrated that the black squirrel is the product of interspecies breeding between the common gray squirrel and the fox squirrel. The black squirrel is actually a gray squirrel with a faulty pigment gene carried over from the fox squirrel that turns their fur a darker shade. (Some fox squirrels, which are usually reddish-brown, are also black.)

A black squirrel is pictured
sanches12/iStock via Getty Images

Scientists theorize a black fox squirrel may have joined in on a mating chase involving gray squirrels and got busy with a female. The black fur may offer benefits in colder regions, with squirrels able to absorb and retain more heat, giving them a slight evolutionary edge.

In North America, black squirrels are uncommon, with one estimate putting them at a rate of one in every 10,000 squirrels. In 1961, students at Kent State University in Ohio released 10 black squirrels that had been captured by Canadian wildlife authorities. The squirrels now populate the campus and have become the school’s unofficial mascot. Their coloring might help them hide from predators, which might come in handy at Kent State: The campus is also home to hawks.

[h/t The Guardian]

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