Are men with more facial hair more fertile?

Chris Smith put this question to biologist Aimee Eckert, from the University of Sussex...

Aimee - Well, the short answer is no. Whilst it’s true that the hormone, testosterone, which everybody produces (men and women), is responsible for beard growth. Men all have a similar amount of testosterone but it’s your individual sensitivity to testosterone that’s different and that is shaped by your unique genetics. A bit like how everyone’s a different height, everybody’s sensitivity to testosterone is a little bit different.

There’s an enzyme that turns testosterone into something call dihydrotesterone, and it’s this form of the hormone that affects people’s hair. This eventually causes, well it can do if you’re very sensitive to testosterone, it can cause the hair follicles on a man’s head to shrink in some people.

So sorry Mike, you’re very sensitive to testosterone. But it’s amazing how it doesn’t affect the follicles on the chin. Like I can see Mike is perfectly capable of growing a beard.

Chris - He’s just got his head on upside down. That’s what it is.

Aimee - So, yeah. It’s the sensitivity to testosterone. A man with a full beard is not going to have more or better quality sperm.

Chris - Sorry to burst your bubble there David.

David - Well, I’d just like to point out that the reason I have a beard is that I can’t afford a diamond tip razor to shave with.

Chris - But presumably, Anna, if you did shave with a diamond razor, then you wouldn’t end up having to keep replacing your frazor every five minutes, which is what inevitably happens? You get about three shaves and then they’re blunt. It wouldn’t blunt.

Anna - Yeah. Technically, it wouldn’t blunt although I think you’d struggle to get a diamond at a very, very sharp angle like you can with a razor blade