Snakes and spiders evoke fear and disgust in many people. Even in developed countries lots of people are frightened of these animals although hardly anybody comes into contact with them. Until now, there has been debate about whether this aversion is innate or learnt. Scientists at the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Leipzig and the Uppsala University have recently discovered that it is hereditary: Babies as young as six months old feel stressed when seeing these creatures—long before they could have learnt this reaction.
Snakes and spiders evoke fear and disgust in many people. Even in developed countries lots of people are frightened of these animals although hardly anybody comes into contact with them. Until now, there has been debate about whether this aversion is innate or learnt. Scientists at the Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS) in Leipzig and the Uppsala University have recently discovered that it is hereditary: Babies as young as six months old feel stressed when seeing these creatures—long before they could have learnt this reaction.
Presumably, in Germany most people have never come across a poisonous spider or snake in the wild. Here in this country there are no spiders that pose a threat to humans. Likewise for snakes there are just two species that are indeed poisonous but they are so rare that you hardly ever encounter them. Nevertheless, there are few people that would not shiver at the thought of a spider crawling up their arm, however harmless it may be.
This fear can even develop into anxiety which limits a person’s daily life. Such people are always on edge and cannot enter a room before it is declared “spider free” or cannot venture out into nature for sheer fear that they may encounter a snake. In developed countries one to five per cent of the population are affected by a real phobia of these creatures.
Read more at Max Planck Institute for Human Cognitive and Brain Sciences
Image: When the babies saw a snake or a spider (second row) instead of a flower or a fish (first row) of the same size and colour, their pupils enlarged significantly (red versus green curve). This is a distinct signal that they felt stressed looking at these animals. (Credit: Max Planck Institute for Human Cognitive and Brain Sciences (MPI CBS))
