Uncontrollable yet predictable, visible yet inexplicable, blushing can be agony when they make us feel upset, embarrassed or just self-conscious.
A new study suggests that a major cause of blushing has more to do with a heightened sense of self-awareness, of feeling seen or exposed, than a cognitive calculation of what other people think of us.
It’s useful to know, thanks to a group of 40 teenagers and 20-somethings made to watch footage of themselves singing karaoke while lying in an MRI machine. Although having more evidence of the link between redness and self-awareness doesn’t necessarily mean we can stop it from happening.
In 1872, Charles Darwin aptly described blushing as “the most peculiar and human of all expressions.” It only intensifies when someone points out that you’re turning a shade of red, while being accused of the act can make you do it too, whether you’re guilty or not.
The explanations for the physiological response are fairly straightforward; a flush of blood to the face that reddens the cheeks, and sometimes the ears, neck, upper chest, and forehead.
But as for why someone blushes, this has puzzled people for years. Is it shame or embarrassment over a clumsy mistake or what might be a well-deserved compliment, or a sense of exposure for all to see?
Do people blush because they suddenly worry about what others think of them and feel judged? Or is it an involuntary emotional response that arises before we have a moment to think about it?
A 2004 study found that flushing could be more intense on one side of the face compared to the other – if someone was looking at the person from the side while singing. But many of these past studies, like the most recent one, are so small that no firm conclusions can be drawn.
“While the attenuation of fear is explicable in terms of the redirection of blood flow from the skin to the skeletal muscles, it is less clear why shame for some socially difficult species should be associated with increased blood flow to the facial area,” psychologist Ray. Crozier wrote in 2010, for the British Psychological Society.
In this new study, Milica Nikolic, a psychology researcher at the University of Amsterdam, and her colleagues tried to address some of these questions about blushing with brain scans of their karaoke singers, showing images of themselves or other people singing.
Surprisingly, only a handful of studies have modeled brain activity in people feeling embarrassed or self-conscious, and while they have observed physiological signs of heightened arousal, none have specifically measured indicators of blushing.
Nikolic and colleagues found that female volunteers’ cheeks got hotter when they watched themselves versus others singing, which isn’t all that surprising.
Functional MRI (fMRI) brain scans were more revealing. They showed that blushing activated areas of the brain involved in emotional arousal and attention, while regions involved in mentalizing—that is, imagining or thinking about your or someone else’s behavior, thoughts, or intentions—were “conspicuously absent.”
“These findings contribute to ongoing theoretical discussions about the nature of flushing and provide support for the idea that higher-level socio-cognitive processes may not be necessary for the occurrence of flushing,” Nikolic and colleagues conclude.
However, the team says their results should be “interpreted with caution” because patterns of brain activity associated with mental processes “as complex and widespread as arousal, attention, and mentalization are not entirely distinct.”
Whether or not these results can be replicated in a larger and more diverse group of people – not just female university students – also remains to be seen. The so-called reproduction crisis has plagued psychological research for decades, in part a reflection of the types of people these studies tend to recruit as volunteers.
The study was published in Proceedings of the Royal Society B: Biological Sciences.