October 21, 2017
Innate Fears: Even Babies Get Stressed When They See Spiders And Snakes

Don't feel bad if you're afraid of snakes and spiders. As it turns out, fear of snakes and spiders is innately human. In fact, even babies get stressed when they see spiders and snakes. Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences say that babies show distinct signs of fear when they see spiders or snakes. This fear is measurable, and babies have these feelings long before they could have learned it from other people, they say.

In some areas around the world, spiders and snakes pose no real threat to human life, but people in these places are still scared of these animals, Science Daily reports. Some people develop major phobias to snakes or spiders. Reportedly, as many as 5 percent of people in developed countries have life-affecting phobias of snakes or spiders.

Researchers at the Max Planck Institute for Human Cognitive and Brain Sciences recently discovered that before infants are able to learn that they should be afraid of snakes and spiders, they have a natural fear of them. Their work was published this week in Frontiers in Psychology.

"When we showed pictures of a snake or a spider to the babies instead of a flower or a fish of the same size and colour, they reacted with significantly bigger pupils," Stefanie Hoehl, lead investigator on the research, explained. "In constant light conditions this change in size of the pupils is an important signal for the activation of the noradrenergic system in the brain, which is responsible for stress reactions. Accordingly, even the youngest babies seem to be stressed by these groups of animals."

Babies have innate fear of spiders and snakes like this one.
A red bamboo snake like this one would likely cause a stress response in an infant. [Image by Panigale/Shutterstock]

Hoehl believed that the fear of snakes and spiders has been inherited. Hoehl says that this fear has an evolutionary origin. Our brains are able to identify and immediately react to things that look like spiders or snakes. The stress reaction actually predisposes humans to see spiders and snakes as dangerous. Now, if these children also had parents with strong aversions to spiders and snakes or if they have a hyperactive amygdala, this natural aversion can turn into a phobia, the team explained.

"We assume that the reason for this particular reaction upon seeing spiders and snakes is due to the coexistence of these potentially dangerous animals with humans and their ancestors for more than 40 to 60 million years -- and therefore much longer than with today's dangerous mammals. The reaction which is induced by animal groups feared from birth could have been embedded in the brain for an evolutionarily long time."
So, while parents need to watch out for more modern safety hazards, children have an innate aversion to snakes and spiders. The team reported that fears associated with ancestral threats like spiders and snakes appear to be stronger and less prone to extinction. The researchers say that their research involving babies' fear of spiders and snakes suggests that humans might have an "evolved mechanism that prepares humans to acquire specific fears of ancestral threats."

[Featured Image by DJack/Shutterstock]