By ensuring that their surroundings were free from spiders, arachnophobes would have had a reduced risk of being bitten in ancestral environments, giving them a slight advantage over non-arachnophobes in terms of survival. However, having a disproportionate fear of spiders in comparison to other, potentially dangerous creatures present during Homo sapiens environment of evolutionary adaptiveness may have had drawbacks.
By ensuring that their surroundings were free from spiders, arachnophobes would have had a reduced risk of being bitten in ancestral environments, giving them a slight advantage over non-arachnophobes in terms of survival. However, having a disproportionate fear of spiders in comparison to other, potentially dangerous creatures present during Homo sapiens environment of evolutionary adaptiveness may have had drawbacks.