Why do we blush and can we control it?

The answer

Blushing is caused by the involuntary dilation of blood vessels in the face, neck, and upper chest, triggered by the sympathetic nervous system in response to social attention, embarrassment, or self-consciousness. Charles Darwin called it 'the most peculiar and most human of all expressions' because it is impossible to voluntarily produce or suppress. The veins in the face contain unique receptors for adrenaline that cause dilation rather than the constriction seen elsewhere in the body during the fight-or-flight response. Evolutionary psychologists theorize that blushing evolved as an honest social signal of remorse or embarrassment that helped maintain group cohesion by demonstrating that the blusher recognizes and cares about social norms. Studies confirm that people who blush after a social transgression are judged more favorably and are more quickly forgiven.