Among the many disadvantages of being pasty white in complexion is the fact that a mere blush can broadcast one’s social discomfort for all the world to see. Granted, people of all colors and ethnicities blush at a basic physiological level—that is to say, human facial veins dilate in response to subtle psychosocial cues. But for mongrelized Caucasians such as yours truly, a white epidermis often acts rather embarrassingly like an objective gauge of subjective discomfort. And there’s not much you do about it, either: blushing is involuntary and uncontrollable.

The good news is that although it may cause you some chagrin, blushing appears to serve a functional purpose. Recent findings by Dutch psychologists Corine Dijk, Peter de Jong and Madelon Peters reveal that if you ever find yourself in a pickle after, say, committing a social offence or being caught in an embarrassing mishap, the presence or absence of blushing can help determine if you’ll be forgiven by others. Surprisingly,these findings, published earlier this year in the journal Emotion , are among the first to address the adaptive significance of the blushing display—what Charles Darwin referred to as “the most peculiar and most human of all expressions.” The gist of Dijk and her colleagues’ evolutionary argument for blushing is as follows:

Publicly conveying embarrassment or shame may signify the actor’s recognition that she/he has committed a social or moral infraction, and regrets this. As a consequence, this message may mitigate the negative social impression that was caused by the infraction.

The authors claim that, much like crying (another peculiarly human expression of social emotion that is difficult to control), blushing serves to signal the actor’s genuine regret or remorse over a wrongdoing. Given the possibility of being deceived, it would have been rather foolish of our ancestors to take at face value a person’s verbal or behavioral expressions of remorse. Instead, over tens of thousands of years, uncontrollable blushing would have evolved as a fairly reliable predictor of the actor’s future behavior. In other words, if the behavior or situation at issue made the person feel so uncomfortable that his or her facial veins dilated—a physiological response that for many people is attended by a somewhat unpleasant tingling sensation—the blusher would probably avoid repeating that behavior in the future. Thus, blushing seems to be an appeasement display. Interestingly, this evolutionary hypothesis is aligned with a recent argument advanced by neuroscientist Mark Changizi in his book The Vision Revolution (BenBella, 2009). Among other things, Changizi claims that our species unusually strong color vision evolved so that we could detect subtle hue changes in other peoples’ skin, thereby deducing their emotions.

To test their own evolutionary hypothesis, Dijk’s group asked 130 undergraduate students from the University of Groningen in the Netherlands to read a series of brief stories about female characters. Participants were told that the woman in the story had either just committed a “social transgression” (such as missing a funeral because of a party, cutting in line at the bakery, driving away after a car crash) or was involved in an “embarrassing mishap” (such as bumping into a rack full of wine glasses, farting in an elevator, spilling coffee on someone). Half of the students were randomly assigned to the social transgression category and read twelve such stories, while the remaining participants read about twelve embarrassing mishaps. Importantly, each brief story was paired with the head-and-neck, color photograph of a different female model (so that there were 24 unique models total) said to be the main character in the story. The students were then asked to rate this woman on a variety of factors. For example, on a scale of 0-100, they were asked to rate their overall impression of this person, how sympathetic they found her, how trustworthy and so on.

Although the researchers investigated several different face presentation variables—such as whether the lady in the image was smiling or gazing downward in shame—the key experimental manipulation was whether she was shown with a blush or without one. (To create the key effect, Dijk and her associates manipulated the images with a computer to make it look like she was blushing.)

The two major findings were these: First, independent of everything else, the blushing models from both the social transgression and embarrassing mishap conditions were seen more favorably by the student judges. That is to say, even for neutral, non-smiling, forward-looking faces, the presence of blushing positively influenced evaluations. Second, when the woman was already exhibiting a shameful or embarrassed facial expression, blushing on top of these displays made her even more likeable.

The authors wrap up their report with the following helpful—evolutionarily informed—advice:

Our results showed that in the context of transgressions and mishaps, blushing is a helpful bodily signal with face-saving properties. It seems therefore unwise to hide the blush or to try not to blush in these types of contexts.

So, by all means—blush, you blushers, blush. You’d be amazed at what this tolerable if mildly unsightly disposition can help you get away with. Nevertheless, I am aware that for some people, these findings are hardly comforting. If your blushing is so awkward that it is completely crippling your social life, and if you’ve already exhausted the array of cosmetic solutions such as wearing camouflaging make-up or developing a fondness for turtlenecks, you might look into having a “bilateral endoscopic transthoracic sympathectomy.” This is the technical term for having the sympathetic nerve that triggers the blush permanently severed. It's rather drastic, but it works—up to 90 percent of patients no longer blush after this surgical procedure. But one of the more common side effects is a potentially even more embarrassing skin problem: compensatory facial sweating. Damned if you do, damned if you don't.

In this column presented by Scientific American Mind magazine, research psychologist Jesse Bering of Queen’s University Belfast ponders some of the more obscure aspects of everyday human behavior. Ever wonder why yawning is contagious, why we point with our index fingers instead of our thumbs or whether being breastfed as an infant influences your sexual preferences as an adult? Get a closer look at the latest data as “Bering in Mind” tackles these and other quirky questions about human nature. Sign up for the RSS feed or friend Dr. Bering onFacebook and never miss an installment again.