Why Do We Blush?

Red like anger, shame and love: many of life’s great emotions are associated with the color red. But what actually happens in our brain when we feel ashamed and why does it make our head turn red?

Suddenly, you get hot, feel paralyzed, and your face turns tomato red – sometimes it’s enough to trip in public to make us feel ashamed. The fact that these symptoms resemble an inflammatory reaction is no coincidence. Shame triggers our immune system, as researchers at the New York Pace University discovered. “The feeling arises in the emotional center of our brain, the limbic system. From here, signals are sent to our body via the autonomic nervous system,” says Melissa Stouffer, neuroscientist and postdoc at the Institute of Science and Technology Austria (ISTA). It controls basic functions such as breathing, heart rate, metabolism, and digestion, and consists of the sympathetic and parasympathetic nervous systems.

While the latter makes us freeze when we feel ashamed, the sympathetic nervous system simultaneously increases the pulse rate and dilates the blood vessels in our facial skin, enabling them to take in more blood. The result: we turn red, a color only very few mammals can see. “Only old world primates, including humans, have evolved trichromatic color vision and thus can see a rich red,” says Stouffer, who studies the development of the human cerebral cortex. Part of it, the orbital lobe, is also likely to play a significant role when it comes to shame. People whose orbitofrontal cortex is damaged do not feel shame. This brain region developed late in human evolution. Researchers assume that it helps to correct our behavior.