If you've listened to enough episodes of Stuff Mom Never Told You, you've probably noticed a few themes (and my propensity for over-using the phrase "if you will"). There's our love of statistics, Slate.com, Jon Hamm and -- somewhat related to that "Mad Men" star -- beards. Molly and I dig beards on boys. Why? Well, science says facial hair makes men appear more trustworthy, for starters. And a pair of studies (via The Daily Dish) also confirm that stubble often makes men more physically attractive. When shown photos of men clean-shaved, stubbled and bearded, women said they'd more likely to hook up with the stubbly fellas for both short- and long-term relationships.
Note that use of "stubble," however. While a light dusting of facial hair adds a sexy, masculine accent to many a male jawline, a full-on, unbridled beard might scare us off. Yet another study (I told you we love studies...) found that bushy beards can hinder communication since they mask facial movements.
Mustachioed Americans are in a league of their own, however. Aside from the hipster set who sport lip hair for irony of it all, Westerners aren't big fans of lip hair. From Neatorma: "According to the American Mustache Institute, mustache acceptance is between 16 and 35 [percent] in the U.S., though between 72 and 94 [percent] in Germany." Again, the communication factor might explain our distaste for mustaches. "A mustache hiding upper lip movement has a larger impact on visual speech intelligibility than a long chin beard, hiding the larynx only."
So really, the best way for men to go is clear: shave the 'stache and beard and keep the stubble. And if someone says it looks unkempt, you've got science to cite.