Men of higher intelligence are likely to produce better sperm, and not because they make smarter lifestyle choices, a new study says. British researchers have found a link between the sperm quality and intelligence of 425 ex-US soldiers, regardless of their age and lifestyle. "This does not mean that men who prefer Play-Doh to Plato always have poor sperm: the relationship we found was marginal," a researcher said.
Scientists had assumed that links between intelligence and health were based on lifestyle. Now, one expert says it starts with "the co-development of brain and testicles when the man was in his mother's womb." Small mutations that hurt brain development may limit sperm quality, or strong genes with an overall "fitness factor" could improve both physical fitness and intelligence, the BBC reports.