I’ve long been interested in the evolutionary roots of much human behavior that we often consder to be a function of culture or social environment… This LA Times article describes the benefits on perception of expressing fear, which no doubt provided an evolutionary benefit to our ancestors.
The look of fear is unmistakable: wide eyes, raised brows, a dropped jaw. But is it more than a social signal?
In this week’s journal Nature Neuroscience, University of Toronto researchers reported that fearful expressions evolved to heighten the senses and improve detection of physical threats.
Scientists asked 20 college students to assume fearful and neutral faces and measured their field of vision each time.
Fearful expressions enlarged the vision field by 7.6% compared with a neutral expression, presumably making it easier to spot an attacker. Scientists also measured eye movements and found that increased scanning took place when students’ expressions mimicked fear.
“When you’re fearful, you need to gather as much information as possible,” said lead author Joshua M. Susskind, a graduate student in psychology.