Intelligent men have healthier sperm, study claims



Bright men have healthier sperm, according to a recent study

It's often been said that men don't think with their brains and now scientists have proved what women thought all along - that a man's sperm quality turns out to be an indicator of his brain power.



Researchers have discovered that men who scored highly in a variety of intelligence tests also had high counts of healthy sperm.

But low scores in intelligence tests showed that men had fewer sperm and that they weren't so healthy.

Evolutionary psychologist Geoffrey Miller, from the University of New Mexico, said: 'It's not necessarily that the same genes are influencing sperm quality and intelligence.

'Rather, the two traits could be linked through a tangled web of biological and environmental interactions that has evolved to help women pick a mate.'

He uncovered the apparent sperm-intelligence connection after re-analysing data gathered in 1985 to assess the after-effects of the Vietnam War, particularly exposures to Agent Orange.

Of the 4,402 veterans who participated in three days of physical and mental testing, 425 provided sperm samples.

After accounting for factors that could skew the results, such as age, drug use, and abstinence before providing a sample, Miller's team looked for a statistical link between men's sperm counts and motility and their scores on several tests of verbal and arithmetic intelligence.



Though the connections between brains and sperm were 'not awesome, they're there and highly significant,' Miller said.

He added: 'I'm thinking of intelligence as being quite closely related to individual fitness.'

About half of our genes are switched on in the brain, so intelligence might provide women with a rough but handy read-out of mutations in our genomes, Miller argued.



Miller revealed his findings at a recent Harvard University talk.