Why are people so afraid of spiders?
Bugs, insects, arachnids—these creatures are big sources of fear and phobias for many people. While some of them are poisonous, others are not. And yet, someone could be as afraid of stinkbugs (non-venomous) as they are of Black Widow spiders (venomous). Why? “Back in the day,” Dr. Dorfman says, “insects represented poisonous creatures whose infectious bites could lead to fatal injury. The brain may be predisposed to anxious responses to these ‘dangerous’ creatures.” So because the brain has learned to associate some spiders with injury or even death, that fear has evolved into a more generalized fear of all creatures that appear similar even if they are not dangerous.
How is fear genetic?
Sometimes fear is out of proportion to what the perceived danger actually is. In a nutshell, that is what people call anxiety. As with other mental disorders, researchers have found that anxiety disorders (and therefore fear) can be influenced by genetics. The Scientific American reports that in mice, fear can be “selectively bred into succeeding generations.” Dr. Dorfman affirms, “Because it is embedded in our DNA, its specific expression can be hereditary.” So fear is developed through the process of evolution, and then it can be passed down through bloodlines. We share common fears because fear literally spreads.
How do we learn fear?
Growing up, children learn from their environment. A significant part of that environment is the people with whom they live, such as parents or other family members. “If a child observed a parent’s anxious response to insects,” Dr. Dorfman posits, “she quickly learns that insects are something to be afraid of, and may be at risk of developing [a phobia or] learning to be phobic.” Combine a genetic predisposition to fear and anxiety with learned anxious behavior and you’ve got a phobia.