The research suggests that spiders presented such a powerful threat to the survival of the first humans that the ability to spot them became an evolutionary necessity.

According to scientists this might explain why people have such a deep rooted and seemingly irrational fear of harmless household spiders today.

A study conducted at Columbia University in New York tested how quickly people were able to identify a spider when dealing with a range of other stimuli.

More than 250 people were asked to study computer screens containing abstract shapes and data and then images known to induce fear or disgust were introduced to test reaction speed.