Fear of heights

In this essay I try to analyze my fear of height through self-inspection and document my experiments in trying to overcome this irrational feeling also known as acrophobia.

First of all, make sure to take this text for what it is, namely the naive, non-expert, non-scientific ramblings of someone with no medical training whatsoever, so please don't hold me responsible if you get some false or harmful information here. You might or might not have a similar condition like me, I have no idea, and even if I had, I wouldn't be qualified to give any advice.

So what is fear of heights (acrophobia)? It seems to be one of those things like autostereograms where if you are wondering if you experience it or not, then it's almost certain you don't. I'm pretty sure I have at least a mild form of it as I am afraid when I look down from heights, but it's not so serious that I couldn't look out from my window. I have climbed some decent mountains and my feelings have ranged from general discomfort to complete panic. The alarming thing was to discover that it's been getting worse recently and I have real difficulty climbing to places where I had no trouble years ago, so I decided I had to do something about it. Just to make sure, acrophobia is when you look out from the balcony on the second floor and feel safer to stay close to the wall or hold on maniacally to anything secure or when you feel dizzy on a mountain trail and you have to crawl on all fours, grabbing every blade of grass for the illusion of safety but you are pretty sure you could fall any moment. If you look down, the world seems to spin and sway, your stomach contracts, you forget to breathe regularly, mouth dries out, you start sweating like a pig and generally panic in every possible way and swear that if you ever get down alive, you'll never set foot on a hill again. Meanwhile your friends are carelessly passing by, jumping from one rock to the other, wondering what the hell is happening to you...

Fear of heights is a misnomer. It is not height per se that I am afraid of. I have no trouble flying in airplanes, I have flown glider planes, I think I could manage parachutes, paragliders or even space flight without acrophobia kicking in. It's not being on high altitudes that I find scary but being in places where I feel I can fall on sharp rocks or buildings and places where I can't easily tell which is the horizontal direction, where I am already not sure if I am standing straight or I am tilting. I'm talking about mountaintops, towers, bridges, balconies. At first I thought that I feel safe in airplanes because my mind tells me there is no way I could fall out, as it is well sealed. On a cliff, if I really wanted to, I could jump voluntarily if I went crazy for a second. This explanation occurs in a bizarre short story of Edgar Allen Poe where he argues that fear of height is really fear of oneself, our "dark side" that would urge us to jump and commit suicide. This "pull of the deep" explanation or the notion of a "latent death wish" seems like a fascinatingly romantic idea to a teenager, but lately I started to become suspicious. Why would I have this sort of split personality or psychological issue that none of my friends seem to suffer from. Surely there must be some more down-to-earth explanation...

The kind of "solutions" people generally suggest are usually of the typical new-age self-help type: healing by exposure, go to the mountains, "believe in yourself", "tell yourself there's nothing to be afraid of", "positive thinking", etc. Those kind of treatments that are supposed to work for everything from insomnia to arachnophobia and shyness to talk to girls. I was pretty skeptical. The more I went to the mountains the less confident and more acrophobic I became. Other popular treatments suggested on the internet include group therapy, meditation, aromatherapy, drugs, anxiety relief. Well, not my kind of stuff. Besides, I might have other phobias in mild forms, but I felt pretty strongly that this is different and a cure-it-all solution won't work.

In a way, fear of heights may seem natural. It is supposed to protect one from falling, by forcing them to avoid dangerous situations altogether. In this way it can even be seen as a healthy dose of caution or survival instinct. Except I don't buy that. For me fear of height is not avoiding any danger, it is the cause of the danger, by not allowing me to stay cool and rational and continue walking on a perfectly safe, not-too-steep hiking trail. What's going on here? Others have said that acrophobia is a conditioned fear, where some past negative experience triggers the panic attack. It is often considered some protective action of the unconscious mind. Even though I've heard of people who have died in climbing accidents, I know this is not the explanation for me. Whenever I felt fear of heights, later it seemed ridiculous, thinking rationally I was certain it was totally unfounded, and I often felt like going back to prove there was nothing to be afraid of, except when I went back acrophobia appeared again. In this sense I don't think it is even correct to classify fear of heights as a phobia. It seems irrational for sure, but it's not the kind of thing that gives you nightmares. I'm not afraid at all of imagining climbing rocks, or looking at pictures or videos taken from high altitudes. So at this point I became pretty certain that if there is an explanation, it has to be some low-level physiological response, related to vision, balance or the motoric system, not a psychological one.

It's time that I tell about another peculiar trait I have, which is not a phobia but something rather pleasant. I never feel sick in a moving vehicle. Not in cars, not on a plane, not on a ship, not in a boat. It can shake and rock and roll and spin as much as it wants, it can be the worst driver and the curviest roads, even if I'm sitting opposite driving direction, I never feel dizzy, never have to vomit. This was something I noticed since my childhood, when I was on a sea cruise and the ship got into a rather serious storm, and I found myself to be one of a few people out of hundreds who didn't feel physically ill even the slightest. Why do I tell all this? Because my hypothesis is that this is pretty intimately related to fear of heights.

The clues came from researching computer vision and reading popular science books about how the brain works. An autonomous agent, be it a robot or a human, has to have some estimate of its own position and orientation in the world as well as its movement and acceleration relative to other objects. Both robots and humans can get this information through several channels. The highest bandwidth channel is of course vision. If I see that everything I know to be horizontal appears to be tilted by ten degrees, I'm quite sure it is me tilting and I quickly balance myself. Of course this is done unconsciously. The vestibular system in the inner ear has sensitive accelerometers that tell my brain when I'm moving and also tell about my orientation relative to the vertical direction. The muscles of the legs also send back messages about various tensions and the direction of gravity. Similarly, robots have accelerometers, GPS's, compasses, etc.

When in a moving car or ship, people feel dizzy because the different sensors send contradictory messages. The inner ear says: we're moving up-and-down. The normal action of the brain in such situations, for example when you jump up-and-down in the room, is to stabilize vision like a good steadycam system, by commanding an opposite movement of the eye: this is the vestibulo-ocular reflex. However when I'm in a car, looking at things inside the car, my eyes say that there is nothing to stabilize. Things inside the car seem perfectly still, as they are moving together with me. Some suggest the brain goes even further and says that the only plausible explanation for this mismatch between what different sensors say is poisoning. Thus the reaction of the body is the one that makes most sense: throw up the poison! That's why it helps to look out of the car, that's why it makes things worse if you read a book in a moving car and that's why you become dizzy if you close your eyes while spinning around.

Long story short, I think the reason why I have acrophobia and why I never feel sick in moving vehicles is the same: I'm relying too much on visuals for balancing, and I don't use the other sensors as much as I should. In an unusual environment, such as when climbing a rock, the visual cues are scarce or misleading. I can't find anything that I know for certain to be horizontal, I don't know for sure what is the vertical direction, there are a lot of rocks of strange shapes around me (not the objects I'm used to seing), etc. So visual cues are next to useless, but I fail to use my inner ear and various muscles for balancing. If I closed my eyes, I'm quite sure I would fall. The fear of heights is just the rational message the brain sends that it is really confused and possibly unable to properly balance the body.

It could be that my other balancing mechanisms are deficient so they don't transmit enough data, but I find it more likely to be a learned (unlearned) behavior. Balancing on one leg I find very easy to do, but if I close my eyes, I tip over immediately. With 5-10 minutes of practice however I can do just as well with eyes closed. I can almost feel that I am using my inner ears and that I start paying attention to the small variations of tension in the leg muscles. The thing to do in the mountains is probably not to pay attention to the visual cues that much. That doesn't mean to close the eyes, just learn to take the vision as a nice panorama to watch, but not something that guides balancing. Watch your step of course, but learn to pay more attention to your ears and legs for balancing. I can't wait to go out and practice.

I'm pretty confident that training in this manner can help overcome fear of heights. Of course, fear of danger has many components and I don't mean to do reckless things or trails that are technically or physically too difficult for me. It is only the irrational part of the fear that I am targeting with this method. I would appreciate comments both from people who have fear of height and from experts in the matter.

[EDIT: 10th Aug. 2009]: If standing on one leg with eyes closed is too extreme an idea, here's an even more unusual one (only half serious): fear of heights glasses.