Arachnophobia is the most common fear of all, and a new study indicates that this fear may have been deeply embedded within us since birth. It explains why people in western industrialized countries where often no one has ever seen a poisonous spider or snake in the wild is still fearful of these creatures.

Researchers say even babies are afraid of images of spiders and snakes, suggesting that a fear of these creatures is built into our brain from an evolutionary standpoint, and that it could have developed as long as 40 to 60 million years ago. And it’s a serious phobia that can limit someone’s daily life, the study found.

This is a unique study in that it specifically examined infants, as past studies had been conducted with adults or older children, so it was harder to determine if this behavior was innate or learned. The study tested whether children could spot spiders or snakes faster than harmless animals or objects, and did not measure fear.

“Presumably, in industrialized countries, especially in middle Europe, most people have never come across a poisonous spider or snake in the wild,” reads the statement from the Max Planck Institute. “In most of this countries there are nearly no spiders or snakes that pose a threat to humans. 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.”