A fear of spiders could be something we are born with rather than something we learn, according to a new scientific study.
Research suggests that arachnophobia could be sown into our DNA as a result of survival instincts developed by our ancestors millions of years ago in Africa.
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.
The study found that people were able to pick out spider shapes uniquely quickly.
One theory is that some of the most dangerous spiders would have been species like the black widow, which are small and difficult to spot, so being alert to the danger became a part of an early human’s survival instinct.
Mr New said: “A number of spider species with potent, vertebrate specific venoms populated Africa long before hominoids ... and have coexisted there for tens of millions of years.
“Humans were at perennial, unpredictable and significant risk of encountering highly venomous spiders in their ancestral environments.
“Even when not fatal, a black widow spider bite in the ancestral world could leave one incapacitated for days or even weeks, terribly exposed to dangers.”
He added: “Detection, therefore, is the critical arbiter of success in such encounters — any improvements to the sensitivity, vigilance, reliability and speed of faculties for their detection would have been of significant selective advantage.”