11/08/2013 01:33 EST | Updated 01/23/2014 10:53 EST

Movember moustaches: why some men can't grow them

Movember is in full swing and many men find only a small dusting of hair on their upper lip, while others are having trouble controlling their new whiskers.

The moustaches being grown by Canadian men this month to raise money for men's health programs can range from pencil-thin to the classic Tom Selleck moustache. But some men just can’t grow them at all. 

CBC science columnist Torah Kachur explored the science behind the ‘stache including:

- Why some men are more talented at growing moustaches than others. (Testosterone isn't as big a factor as you might think.)

- Why dark-haired men often have reddish facial hair.

- How facial hair affects men's sexual attractiveness to women.