Treating your fear of spiders could fix your fear of heights

Fears don't typically come in isolation; if you're scared of one thing, research suggests you are more likely to be scared of other things too. Sometimes those fears share characteristics or categories, like a fear of spiders extending to fear of insects. This phenomenon is sometimes referred to as 'fear generalisation'. 

These other fears aren't always similar, however — our phobias can be spread across many different things that seem to have no real connection. 

Many of our fears can be improved by exposure therapy, a treatment which allows people to confront individual, specific phobias in manageable stages. But could exposure therapy behave similarly to fear generalisation – easing our nerves across multiple, unrelated phobias? Writing in Translational Psychiatry, Iris Kodzaga and colleagues find evidence that this may indeed be the case, unlocking new understandings for how we treat phobias. 

Participants for this study were adults aged between the age of 18 and 40 who reported a fear of both spiders and heights, and who scored highly on measures to determine the level and intensity of these fears in a pre-assessment survey. Any person with acute mental health issues was screened out from the study, so participants did not have particularly high levels of generalised anxiety. 

Data was collected across several appointments: at each, participants completed standardised fear of spiders questionnaires, which cover levels of fear in terms of physiological reaction, subjective evaluation of fear, and level of avoidant behaviour.      

After the pre-assessment, participants were split into exposure and non-exposure conditions. Those in the exposure condition took part in a behavioural approach test (BAT) for both spiders and heights to further measure their fear. 

The BAT for spiders required participants to approach a spider as quickly and closely as possible, until they became too afraid to go any further. Scores were given based on distance away from the spider — for example, 0 points were given if the participant refused to even enter the room, whereas they received 13 points if they were able to transfer the spider from a terrarium to a jar. 

For the heights BAT, participants were asked to climb up a local church tower, again until their fear prevented them from going further, and were scored on which pre-determined station they had reached. 

One week later, participants in this condition took part in exposure treatment for their fear of spiders. The treatment involved fourteen steps, with increasing levels of difficulty — the first step, for example, was watching the spider inside a closed jar from a distance, before moving closer, looking at it in an opened jar, touching it with a pencil, holding it in a gloved hand, before finally holding it in a bare hand. 

Fear levels were rated at the beginning and end of each step. Each was repeated until fear was under a certain level, and treatment was completed when either all the steps had been completed, or two hours had passed.

One day after the treatment, the exposure group completed a post-assessment, undergoing the two BATs and rating their fear again, as well as completing the spider fear-related questionnaires from the pre-assessment. Those in the non-exposure condition completed all of the steps above minus the exposure treatment. 

Although a fear of animals and a fear of heights are unrelated, the results suggested that exposure therapy targeting spiders also improved participants' fear of heights — participants that did the spider exposure therapy also climbed to greater heights. This suggests that the therapy did generalise. 

Interestingly, there were no significant changes in subjective self-assessments of fear, despite the fact avoidance behaviour was reduced. The team note that behavioural responses "often show poor correlation with subjective states", meaning participants may experience an ongoing change in behaviour before their levels of subjective fear decrease. This decrease, they argue, is likely to be the conclusion of "mastery and emotion regulation experiences... made possible through the reduction in avoidance behaviour." That is, initial changes in behaviour are what makes changes in emotional experience possible. Longitudinal studies may uncover whether this is the case.

Though it's not exactly clear why exposure to one fear may allow us to make progress with another, one theory is that exposure therapy allows us to develop emotional tools that can be used across all kinds of fear-eliciting stimuli, attenuating fear even towards something we have not been exposed to. 

One limitation of the study is its short-term nature — it would be useful to see how long exposure therapy works both on its direct target and on unrelated fears. As noted, the team excluded participants with anxiety disorders or other mental health conditions; future research could look at how such therapies work alongside other, co-existing conditions. 

Overall, however, the results could represent an incredibly practical addition to our knowledge on phobias and their treatments. Exposure therapy is not always an easy thing to undergo, particularly for those with strongly avoidant behaviours. Having treatments work on more than one fear at a time, therefore, could reduce stress for patients whilst also helping them live happier lives.  

Read the paper in full.