Dec. 16, 2008 at 6:45 PM ET
By Brian Alexander
It may seem counterintuitive to those males among us who spent more time in high school reading Dickens or studying calculus than we did making out with Stephanie the cheerleader, but a group of researchers has issued a study finding that higher IQ men have better sperm.
Take that, Mr. Quarterback.
But before the pocket protector set starts strutting in their Radiohead T-shirts, hang on a minute. As interesting and possibly important to a certain subgroup of scientists as the study may be, it says much more about our obsession with grading our masculinity than it does about brains and sperm.
The point of the study was to test a theory about “fitness factor,” explained lead author Rosalind Arden of King’s College, London. Fitness factor, according to the researchers, involves the clues, such as waist-to-hip ratios, that signal we have good genes in general and will produce tip-top babies.
“I chose to analyze the relationship between sperm and intelligence because I thought that if we were serious about the fitness factor idea, then even two [apparently] unrelated traits might be correlated,” she said. In other words, they didn’t set out to prove that smart men have better sperm.
“The bigger idea of the fitness factor,” Arden explained, “is that beauty, health, intelligence, personality - may all exist in a giant web - traced out by the spider of evolutionary fitness.” In other words, one gene or big set of genes that may bestow some fitness traits, like body symmetry, may also confer less obvious ones, like good sperm.
Conveniently for the researchers, in 1985 the U.S. government conducted something called the Vietnam Experience Study, in which war veterans underwent a battery of tests, including intelligence and various physiological measures. Some of the men supplied semen samples. Arden and colleagues examined the data to correlate IQ with semen. It turned out that there was a small link between higher IQ and better semen.
So, smarter guys tend to have higher quality sperm, they found. But the reality is, there is no intellectual push-up a man can do to give himself better— that is, more fit or more aggressive sperm.
“If you’re going to be a Go Master,” Arden said, making a pun of a movie about a genius of the Chinese board game, “do it for the love of the stones - not to improve your sperm quality.”
We’d make our sperm happier just by wearing boxers rather than tighty whities and letting those boys breathe.
While the researchers judged quality based on number, density and swimming ability, sperm experts — also known as andrologists — consider other factors to be equally important to fertility, like how the sperm interacts with an egg. The shape, structure and health of the sperm are also important. A normal sperm has a long tail and an oval-shaped head that whips it forward to the egg.
To get healthy sperm, it's recommend that men take a daily multivitamin with selenium, zinc and folic acid, nutrients that are important for sperm function, according to the Mayo Clinic. Guys should also exercise regularly and maintain a healthy weight. Smoking tobacco, pot or drinking too much alcohol can wreak havoc on sperm. Same for stress and steroids.
So, practically speaking, while possibly important to science, the study doesn’t mean much for the average guy. It is, Arden said, “akin to one tiny piece in one of those god-awful humungous jigsaws given by well-meaning aunts as 'improving' Christmas gifts to small boys.”
But the study did reveal a lot about human psychology. To read some of the breathless press coverage, it was a eugenicist’s dream come true. “There are few better ways of upsetting a certain sort of politically correct person than to suggest that intelligence (or, rather, the variation in intelligence between individuals) is under genetic control,” The Economist gleefully noted.
Yet cause-and-effect is not nearly so clear cut. Genes do influence intelligence and a number of studies have linked higher intelligence with better health, according to Douglas Detterman, a professor of psychology at Case Western Reserve University and editor of the journal Intelligence, in which Arden’s paper appeared. For example, higher IQ men have been shown to have less risk of dying of coronary heart disease. Such findings have spawned a new field called “cognitive epidemiology.” But nobody knows why it occurs.
“There is a lot of speculation,” said Detterman. “It could be that people with lower IQs receive inadequate treatment. Perhaps they require more instruction on how to follow doctors’ orders.”
It might also be that people with lower IQs aren’t inherently less fit; they just make less money and cannot afford top quality care. “Disentangling all these factors is complicated,” he said.
So it looks like smart boys are going to have to stick with bait like Shakespeare’s sonnets and Ferraris bought with proceeds from inventing high-tech gadgets to attract the women with whom we’d like to share those sperm.