I had been intending to do a post on phobias for a few weeks, when fellow EvoS Blogger Kaitlyn Andersen came in and scooped me on it. For reasons mentioned by Kaitlyn, the area of phobias is one very obvious application of evolutionary thought into clinical psychology. Let me recap very quickly here.
In lab experiments, humans (and monkeys) tend to acquire fear reactions to certain stimuli more readily than to others. Which stimuli are we most prone to fear? Those which would have been threatening in the natural environment of our ancestors (human and pre-human). The notion, of course, is that a predisposition to fear (and thus avoid) certain classes of stimuli can become evolutionarily selected for if those stimuli can kill you. Think of venomous and predatory animals (snakes, spiders, wild dogs) and situations like being dangerously high off the ground.
Not surprisingly, phobias of these flavors are the most commonly presented in clinical settings. Over many generations of evolutionary time, we have become “biologically prepared” to fear stimuli that were dangerous for our ancestors. However, crucially, our complex cognitive systems have not had time to evolve biological preparedness to fear things which are truly harmful in this day and age. Phobias of guns, knives, fast-moving cars, electrical sockets, corrosive acids, cocaine, and Luther Burgers would save a lot of lives if we had them, but such phobias are in fact quite rare. Maybe after another 100,000 years, people who tended to react phobically to such stimuli will have left more offspring, all of whom will be biologically prepared to fear these modern dangers.
Okay, so that’s all very Psych 101. But what about all those other phobias you read about in the Fun Facts on the back of cereal boxes? Ones like arachibutyrophobia (fear of peanut butter sticking to the roof of your mouth), bufonophobia (fear of toads), coulrophobia (fears of clowns—a relatively common one, actually), or metrophobia (fear of poetry)? As has been pointed out by smarter people than I, most of these tend to be rare, idiosyncratic, or virtually nonexistent. So many of them exist (in lists like this) because it’s fun for linguaphiles to coin and compile them.
But notice I said virtually nonexistent. Some people still have reactions to (often completely non-threatening) random stimuli that could be classified as phobic, contra some claims that only biologically prepared stimuli can be phobically conditioned. How? Why? Perhaps the answer is that we have two separate phobia systems. We are “biologically prepared” to fear certain objects/animals/situations that were dangerous to our ancestors. But we can acquire conditioned responses to novel stimuli as well, and this may be thought of as a second way that we form phobias. It is a fairly efficiently designed system, after all: program the organism to fear stimuli that were recurrently present and dangerous in the past, but also allow it to form new fear associations to any particular stimuli which are paired, during the organism’s life, with a profoundly negative experience.
So does this two-mechanism system, and the predictions thereof, accurately describe the diversity of clinical phobic responses?
And also: geniphobia – fear of chins.