Smart men may produce better sperm

After ruling out factors like age and lifestyle, researchers found a link between higher intelligence and all three measures of sperm health: number, density and mobility.

The link was not that strong, but researchers say the results support the importance of the "fitness factor idea", which suggests that genes work together to make certain individuals fitter, healthier and smarter.

- Get more L.A. breaking news, weather, traffic and sports
- Have a news tip? Send your tips, video, or pictures