Spiders and snakes are gross and scary. Even in developed countries, most of the people are scared of these animals. The disgust and cultural history in spider and snake phobia suggest that such fear may have a complex origin. A new study sheds light on it and suggests that it is actually hereditary.
Even a six-month-old baby can scare and feel stressed when seeing these creatures. Scientists at the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Leipzig and the Uppsala University conducted the study.
In Germany, most of the people have never seen a poisonous spider or snake in the wild. In this country, there are no spiders that cause harm to humans. Similarly, there are only 2 species of snakes that are indeed poisonous. But, they also found rarely.
Scientists suggest that the fear can also develop into anxiety which limits a person’s daily life. It is still unclear from where this widespread aversion or anxiety stems arise. According to many scientists, the fear arises in our childhood from our surroundings.
In this study, scientists made a crucial observation. Even in infants, a stress reaction is evoked when they see a spider or a snake.
Stefanie Hoehl, lead investigator of the underlying study said, “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 color, they reacted with significantly bigger pupils. In constant light conditions, this change in the 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.”
“We conclude that fear of snakes and spiders is of evolutionary origin. Similar to primates, mechanisms in our brains enable us to identify objects as ‘spider’ or ‘snake’ and to react to them very fast. This obviously inherited stress reaction, in turn, predisposes us to learn these animals as dangerous or disgusting. When this accompanies further factors it can develop into a real fear or even phobia.”
“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.”