Health & Science

Are humans getting dumber?

As a species, we’re not as smart as we used to be. That’s the theory of a Stanford University researcher who believes that human intelligence started to decline when civilization made life easier and allowed dimmer individuals to survive and pass on their genes. “I would wager that if an average citizen from Athens of 1000 B.C. were to appear suddenly among us, he or she would be among the brightest and most intellectually alive of our colleagues and companions,” Stanford geneticist Gerald Crabtree tells The Independent (U.K.). He figures human beings reached their intellectual peak 2,000 to 6,000 years ago, when life was so harsh and individualistic that bad judgment generally led to death. Farming progressively led to denser communities where people could collectively ensure one another’s welfare. As a result, evolutionary pressure—the hunt for prey, the avoidance of predators—no longer culls the slow-witted the way it once did. “A hunter-gatherer who did not correctly conceive a solution to providing food or shelter probably died,” Crabtree says, “whereas a modern Wall Street executive that made a similar conceptual mistake would receive a substantial bonus and be a more attractive mate. Clearly, extreme selection is a thing of the past.”

Making objects undetectable

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It’s still a long way from Harry Potter’s invisibility cloak. But researchers have taken a crucial step in that direction by designing a device that can render a 3-inch-wide cylinder undetectable by microwave radiation. Previous devices have faltered by reflecting rather than redirecting some waves; this new design resolves that knotty problem, making it the first cloak that is able to “get you that perfect invisibility,” Duke University electrical engineer David Smith tells BBCNews.com. The diamond-shaped cloak, made of specially fabricated “metamaterials” that don’t exist in nature, bends microwaves around an object, effectively hiding it from detection. The cloak can only conceal objects when they’re viewed from a specific direction, and it doesn’t hide them from visible light. But the new design “could be potentially useful,” Smith says, in making aircraft and submarines invisible to radar signals, which use microwaves. And researchers may one day figure out how to apply the design to hide objects from sight. Says Smith, “I think it’s something that a lot of people can build on.”

Is soccer bad for the brain?

Young boxers and football players may not be alone in facing possibly permanent damage to their developing brains by taking blows to the head. A surprising new study suggests that soccer players could be at similar risk. Harvard Medical School researchers used high-resolution imaging to examine the brains of 12 elite adult soccer players and a similar number of competitive swimmers. Though the soccer players had no symptoms of brain injury and no known concussions, the scans showed damage to the brains’ white matter, which contains signal-transporting nerves vital to memory and attention. The swimmers showed no such changes. The damage “could be from heading the ball, or due to the impact of hitting other players or from sudden acceleration,” study co-author Martha Shenton tells USNews.com. And that could have “tremendous public health implications” for the millions of boys and girls who grow up playing soccer in the U.S., as well as for those who play other contact sports, says University of Rochester Medical Center physician Jeffrey Bazarian. The researchers said they wouldn’t discourage children from playing soccer, but urged further study into how the damage occurs and what long-term effect, if any, it might have.

Meditation’s health benefits

Meditating—the practice of sitting quietly and clearing the mind of all thoughts—could dramatically improve heart health, a new long-term study suggests. Researchers divided 200 adults with heart disease into two groups: One group was taught to meditate for 20 minutes twice a day; the other group was encouraged to spend a similar amount of time exercising and preparing healthy meals. After nearly a decade, researchers found that those who had meditated for the recommended time had reduced their risk of heart attack and stroke by 66 percent compared with those who hadn’t. The risk for those who meditated only eight times per week dropped by nearly 50 percent. The meditators also reduced their blood pressure and reported feeling better able to control their anger. “What this is saying is that mind-body interventions can have an effect as big as conventional medications,” study author Robert Schneider, director of the Institute for Natural Medicine and Prevention, tells WebMD.com. Indeed, previous studies have shown that “meditation can do a whole host of positive things: reduce anger and stress, encourage happiness,” says cardiologist Michael Shapiro. But, he adds, researchers still “don’t know how it works.”