For centuries, bearded men have argued that facial hair is nature’s insulation, and therefore a handy wintertime tool. They oftentimes point to this 2012 study, which found that regularly-shaved upper lips are an average of one degree warmer than hairless cheeks, as proof. There are just two problems: This study is irrelevant, since both the upper lips and the cheeks were hairless when the temperature was recorded, and these same bearded men also conveniently claim that (come summertime) beards don’t provide enough insulation to increase the average temperature of the face.
So, which is it? Do beards keep you warm, or don’t they? Science points to the latter.
As we learned in a previous article, which explored whether or not manscaping can keep you cool, we simply don’t grow enough hair to meaningfully affect our temperature:
“According to a study titled Hair Density, Wind Speed, and Heat Loss in Mammals, skin needs to be covered by at least 1,000 hairs per square centimeter in order for the hair to effectively reduce heat loss: That’s the same as a rabbit’s pelt — for comparison, the average adult human head has only 200 to 300 hairs per square centimeter.”
Other research backs up this claim: A 2015 study found that even the hair on our heads — which is the most abundant growth of hair on the human body — is incapable of preventing heat loss, and a 2014 study claims that, “Human hair provides little or no thermal insulation.”
So why does it feel like a beard keeps us warm, and shaving it keeps us cool? For this, we blame the placebo effect, a phenomenon in which a person perceives an improvement due simply to their expectations, rather than the treatment itself. It’s important to point out here that the placebo effect is a real thing, as explained by clinical pharmacologist Daryl Davies in an interview with MEL Magazine: “The placebo effect isn’t artificial — it’s still an effect,” he says. “A placebo has powerful changes in behavior, so just having a patient think they’re getting a benefit [or, in this case, a man thinking shaving keeps his skin cool] has a remarkable capacity to induce that benefit”
All in all, this leads us to conclude that beards have zero effect on body temperature — unless, of course, you shave off every beard attending the The World Beard and Moustache Championships and knit them into a large winter coat.