New research is suggesting that beards are considered more attractive when fewer guys have them, but when more men start wearing beards, it's less attractive.

The study published in the Royal Society journal Biology Letters also says evolution may be playing a role in the rise and fall of beards and other facial fashions.

In evolution, when a gene or trait is rare it experiences an advantage, but if it's too common there's a disadvantage.

The same appears to be true for beards, mustaches, goatees, sideburns and so on.

--Rob Archer