Understanding Phobias
How evolution and neuroscience can explain our fears of snakes, spiders & heights.
How we evolved phobias
People tend to develop phobias of things which would could have been harmful for our ancestors, such snakes, spiders or heights. In contrast, it seems to be much rarer to have a phobia of things which have only recently presented a danger, e.g. cars, guns or electricity. It may be the case that evolution has prepared us to fear certain harmful things and ignore others — (Seligman, 1971)
For most of you reading this, snakes, spiders and heights are unlikely to be significant dangers in your every-day life. You are much more likely to die from being run over by a car. While a fear of snakes is commonplace, a genuine phobia of cars is rare.
This phenomenon can be explained in evolutionary terms. To explain how, I want you to think back hundreds of thousands of years. Back to a time when it was more difficult to avoid snakes and their aggression.
Human A is walking to get some water. They see a snake 10 metres away. He is not scared of snakes and so he continues walking in a straight line as usual. Human A gets bitten by a snake. Human A isn’t going to be able to reproduce and pass on his genes. Human A fucked up.
Human B is making the same walk for the same purpose. He sees the snake 10 metres away. Human B is terrified of snakes and immediately D-tours away from it. Human B lives to pass on his genes, the same genes that may well initiate the same phobia in his child.
Snakes, spiders and heights are the most common phobias today because of the survival advantage they provided to our ancestors. Studies have shown that these fears are often present from a very early stage in life. Babies gain a fear of heights at around 6 months, which coincides with the time period where they learn to crawl. Fear of snakes and spiders are also common in babies of this age.
Phobias in relation to the brain
Fear is attributed to the amygdala, of which there are two.
Experiments have been done with monkeys where they remove these amygdalae. They found that these monkeys lost all sense of fear, and it would cause them to be aggressive to snakes.
When we experience fear, there will always be a stimulant for that fear. For example, the stimulant could be a spider. The arachnophobic will see the spider with their eyes. Sensory information they intake is first fed to the thalamus. The thalamus then relays this information to two different parts of the brain. The first is the cerebral cortex, which is a part of the brain associated with consciousness. The other part is the amygdala, the sub-conscious part of the brain associated with fear. Therefore our response to fear can be governed by either our conscious mind, subconscious mind, or a combination of both. The conscious mind is slow and logical, and we need time to think about the threat before we take action. In the case of phobias, we often react subconsciously. For example, the arachnophobic’s initial response may be to instantly run away from the perceived threat. This is known as an amygdala hijack. The amygdala essentially prevents the conscious mind from thinking about the situation, instead it forces the body into a fight, flight or freeze situation. The more times the arachnophobic responds in this way, the more likely they will respond the same way in the future. This is because the connections being made in this subconscious response strengthen every time.
What we can do about it
If we don’t address our phobias, the phobia gets stronger and the response becomes faster and more automatic. The solution to this problem is to first be self-aware that this is happening. A person with a phobia is likely to interpret the stimulus as more of a threat than it actually is. The first step is to realise that this is the case, and then to spend time assessing the situation. By doing this, we give our conscious mind a chance to make a rational decision. Going back to the arachnophobia example. If instead of running away the person takes the time to assess the threat, they can override the fight, flight or freeze subconscious response. They may decide that it makes more sense to catch the spider in a cup, and release it elsewhere. By doing so, the next time they encounter a similar situation they are more likely to take the time to respond in a rational way. Doing this repeatedly will severely reduce the phobia at hand.
