Humans seem to be the only animals to show
embarrassment, leading Charles Darwin to describe
blushing as “the most peculiar and most human of all
expressions”. Blushing makes it harder to lie, which
seems like a disadvantage. However, a 2009 study by
Dutch psychologists found that we are more likely to
give people a second chance if they blush when they
betray us. The ability to blush acts as a signal that you
are sensitive to the social rule you have just broken.
Psychopaths, on the other hand, do not blush at all.