Fear of snakes is one of the most common phobias, yet many
people have never seen a snake in person. So how is this fear generated?
New research suggests humans have evolved an innate tendency
to sense snakes — and spiders, too — and to learn to fear them.
Psychologists found that both adults and children could detect
images of snakes among a variety of non-threatening objects more quickly than
they could pinpoint frogs, flowers or caterpillars. The researchers think this
ability helped humans survive in the wild.
"The idea is that throughout evolutionary history,
humans that learned quickly to fear snakes
would have been at an advantage to survive and reproduce," said VanessaLoBue, a post-doctoral fellow in psychology at the University of Virginia.
"Humans who detected the presence of snakes very quickly would have been
more likely to pass on their genes."
Previously, anthropologists havesuggested the need to notice snakes in the wild may have led early primates
to develop better vision and larger brains.
Eew!
The researchers were inspired to investigate the fear of
snakes when they thought about how universally people dislike the slithering legless
lizards.
"This feeling is really common," LoBue told LiveScience. "We don’t see snakes
all the time. There's really no reason for this overwhelming disgust or hatred
of snakes."
LoBue's collaborator, Judy DeLoache, a professor of
psychology at the University of Virginia, happens to be petrified of snakes.
"I have almost a phobia of
snakes," DeLoache said. "When I see a picture of a snake, I'm like,
"Oh my God, eew! The reason we got into this research was because I've
always been fascinated by how it is that people develop it. My intuition was
that there was something that made me feel afraid of snakes early on. You react
to them very early on."
While babies and very young children do not usually fear
snakes, they are unusually skilled at detecting them and show a predisposition
to learn to fear snakes if they have bad experiences or even if they are
exposed to negative portrayals of them in the media, the scientists found.
Spiders, too
To learn more, the psychologists showed adults and 3-year-old
children images of a snake surrounded by objects of similar colors, such as frogs,
caterpillars and flowers. Then they showed them pictures of a frog or a flower
surrounded by snakes. Both groups were able to identify the hidden snake faster
than the other hidden objects.
"We also did a study with spiders and found the same
effect," LoBue said. Although the team has not tested other phobias, they
don't think these predispositions would necessarily apply across the board.
"It would have to be something widespread, that you
could encounter on a day-to-day basis," she said. "That’s why you
don’t see lion and tiger and bear phobias as often. It would also have to be
something that was around and dangerous while humans were evolving. Things that
are dangerous right now, like guns, we haven’t had enough time to develop a
predisposition to detect really quickly."
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