Health & Science

Why tennis players shriek and grunt

Tennis players and fans alike can’t help notice the growing din on court. Maria Sharapova’s shrieks of exertion have been measured at 101 decibels, louder than a jackhammer (100 decibels), Serena Williams (88.9), and even the famously loud Monica Seles (93.2). Quieter players accuse the shriekers of deliberately trying to distract them. But does making a loud noise while hitting the ball actually help? Quite possibly, says ScientificAmerican.com. In a recent study, physical-therapy researcher Dennis O’Connell found that by grunting, college players could speed up their serve by 4.7 mph on average and their forehand by 4 mph. He notes that the grunt occurs during what is known as the Valsalva maneuver, when a tennis player—or a weight lifter—forcefully expels air in moments of extreme muscle strain. Grunting appears to recruit more muscle fibers to the activity, thus generating more force, and “can have a role in helping anyone do a maximal exertion,” O’Connell says. The advent of grunting in tennis, meanwhile, may be a response to technology: Today’s rackets deliver far more power than those in the old, quiet days, and so demand a stronger return from the opponent, grunt and all.

How to have a rotten marriage

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When it comes to choosing a mate, studies have shown, people gravitate to a partner with personalities and values similar to their own. But money is another matter: New research has found that penny-pinchers and spendthrifts often wind up together, and that it’s not always for the best. Researchers analyzed several studies in which married couples interviewed apart were asked to describe their feelings about spending money. The more of a spendthrift or tightwad each spouse was, the more likely he or she was to have married someone with the opposite approach to money—perhaps out of hope their mate would balance them out. But the researchers found that these marriages of opposites result in a lot of conflict and little long-term satisfaction. That hardly should come as a surprise, researcher Eli Finkel tells The New York Times, but “we seem to have approximately no introspective accuracy as to what it is we want in a partner.”

Tears as a survival strategy

Whether in pain or in sadness, the shedding of tears is a uniquely human trait. But what’s the use in crying? Several possibilities have been floated: Tears carry stressful chemicals from the body, or help a baby signal distress to a caretaker. Oren Hasson, a biologist at Israel’s Tel Aviv University, has advanced a new theory: By blurring vision, tears naturally stymie one’s aggressive impulses and so signal vulnerability to other people. By acting as a white flag signaling helplessness, crying may elicit mercy, sympathy, or even help, and thus aid our evolutionary survival. Hasson’s explanation “offers the most plausible hypothesis about the evolved function of tears and crying,” evolutionary psychologist David Buss tells LiveScience.com. “The notion that they operate through handicapping is highly original.”

The origins of ‘eek!’

Many people are afraid of spiders and snakes, but girls may be genetically predisposed to the fear, a new study suggests. Researchers at Carnegie Mellon University showed images of spiders, fearful faces, and happy faces to 11-month-old boys and girls. Girls showed a special fascination with spiders, and seemed to inherently associate them with fear. Study author David Rakison tells Science News that in our hunter-gatherer past, it was evolutionarily useful for girls to recoil from spiders and snakes, whereas men needed a higher tolerance for physical danger in order to hunt successfully. The fact that there is no gender difference in modern phobias—such as fear of flying—supports that theory, Rakison says.

Butter from 1000 B.C.

Workers in an Irish peat bog unearthed one of the oldest and best-preserved examples of packaged food: a 3,000-year-old oak barrel filled with butter. The barrel, which had been cut from a tree trunk, was 3 feet long, weighed nearly 80 pounds, and came with lid attached; the butter had long since turned into a white, waxy substance called adipocere. “We knelt down and felt something hard and started to dig it out with bare hands,” John Fitzharris told the local paper, the Leinster Leader. “We could smell it, and it was attracting crows.” Numerous well-preserved bodies, food items, and tools have been found in peat bogs, which are famously devoid of the oxygen and acids that cause decomposition. The barrel of ancient butter is now being analyzed at the National Museum of Ireland, where conservator Carol Smith said the testing does not include tasting. “It’s a national treasure,’’ she said. “You can’t be going hacking bits of it off for your toast.”