Indiana Jones has a famous fear of snakes, but he’s not alone – an estimated 1/3 of adults also suffer from ophidiophobia. As it turns out, we all have a heightened instinct to spot snakes wired into our brains. Here, a snake emerges from a form of camouflage in a series of pictures shown to human volunteers. They were able to spot snakes earlier in the sequence than similarly sneaky pictures of less threatening animals – fishes or cats. The theory goes that human alertness to snakes evolved from primates – from a time when snakes were deadly predators and only sharp-eyed snake spotters survived. This heightened alertness may provide new insights into the psychology behind the fight-or-flight response. Strangely the study also revealed a mystery – just as humans have evolved to react faster to snakes, our reaction to birds may be slower than expected, and for the moment nobody knows why.
Written by John Ankers
BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.