What is the evolutionary purpose of blushing? Peter Walls, Liverpool
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Readers reply
I’m too embarrassed to say. 321bytor
Dinosaurs didn’t blush and look what happened to them. mrfloydthursby
It most likely has to do with confrontation. It’s a visual way of expressing remorse, embarrassment, or showing that we’re not being confrontational. Most species have developed non-verbal ways of expressing themselves; humans are no different. MicheleWalker
There’s an assumption in the question that it’s a non-verbal signal, but it might be just a side-effect of experiencing socially activated stress, which raises your blood pressure. Your body then combats this with vasodilation (the widening of the arteries and large blood vessels), which decreases systemic vascular resistance, enhancing blood flow and resulting in a counterbalancing reduction in blood pressure. This might be the underlying physiological process that evolution has developed, but, over time, we have incorporated its visual side-effect into our complex web of interpersonal communication, completely outside evolutionary pressure. HaveYouFedTheFish
I work a lot with blushing as a psychotherapist. My take is that it’s part of our childhood – and survival; an informed need to stay connected to, and therefore protected, nurtured and fed by, our primary caregivers, without whom we as babies and children are literally a predator’s lunch. Blushing signals shame, or a felt sense of guilt, which communicates to the caregiver that the child has internalised the bad thing that is happening as its fault and not that of the caregiver. This ensures the continuation of at least basic care – and thus survival.
Understanding the skin as the principal organ of communication for all of us, especially as children, I find in my psychotherapy practice that so many skin conditions, from constant blushing right up to eczema and acne, have their roots in early childhood formative experiences, rendering these old stories amenable to trauma-informed treatment with, in my case, eye-movement desensitisation and reprocessing – often with striking effectiveness. Mark Brayne
I have no evidence regarding blushing whatsoever, but all core emotions trigger behaviours which preserve the family or extended family group. They are rooted in the limbic (hormonal) system and they predate cognitive thought. They also served to communicate at an evolutionary stage before speech: “love”, or attachment, served to make us care and look after one another; shame resulted in the shamed one withdrawing to the edge of the group. It served to reinforce the core rules of the group. When someone got caught stealing food from a child, they might experience shame. It was then for the others in the group to invite the shamed one back into the group. All emotional responses have a function and behaviour attached. So, blushing? Perhaps it is a small shame thing, or a signal that boundaries have been crossed. Clibanus
I can blush when I am by myself, especially at the recall of something embarrassing, so it’s not just to do with being in a group. Its frequency is lessening as I get older, but definitely still there. Jotey
We’re assuming evolutionary purpose just because evolution hasn’t yet eliminated it? Sounds tenuous. Might as well ask the evolutionary purpose of a limited literary experience. At least blushing makes you look well red. CiderDemon
There doesn’t have to be an evolutionary answer to everything. Some things are just consequences of others without any selection pressure; others are simply neutral changes that are the consequence of random drift; and some are indeed selected for by natural selection or other selective pressures. JohnRobinson
I’m reminded of Steve’s line to Susan in the romantic sitcom Coupling. After losing his ardour, Steve (played by Jack Davenport) complains to Susan (Sarah Alexander) that she’d made him blush: “No one has that much blood!” ClareM8
