Fear of heights develops in the same way as any other specific phobia i.e. the sufferer has previously linked the raised arousal, felt when confronted with being high up, with tense muscles and negative thoughts. This has taught the survival instinct that this is a situation to be feared. It therefore ensures that whenever the person encounters a similar situation, it will give a startle warning. If the person then responds to this with more negative arousal the phobia starts to develop.
Is it Normal to be Afraid of Heights?
It would seem that humans have an inbuilt wariness of heights but not necessarily a fear of them.
There is an old experiment called the 'Visual Cliff' quoted in basic psychology textbooks. In this experiment a floor and large tabletop area are covered in a chequered patterned fabric. The top surface of the table is continued to the wall by means of a sheet of plexiglass. A crawling baby is placed on the table top. The baby will typically crawl over the solid tabletop but will refuse to venture onto the glass.
It is assumed that this is because the baby has an inherent wariness of the apparent drop where the opaque surface ends and the glass begins. This experiment has also been repeated with other species with the same effect.
This video shows a variation on the original experiment by Gibson and Walk in 1960. This time the effect of the mother’s behaviour is shown in that if the mother looks scared the baby will not cross what appears to be a cliff edge. If, on the other hand, the mother is encouraging, the baby braves the journey.
This instinctive wariness is not the same as a fear. A fear will only develop if the baby experiences some negative arousal at the sight of the apparent cliff edge. If the baby merely decides to crawl away again, without this negative arousal, there will be no fear.
If we are all born with some degree of wariness of heights, why do some of us go on to develop a phobia?
If we have a particular negative experience associated with a particular type of high place e.g. we may fall down the stairs, fall out of a tree, fall off a roof etc. then the next time we find ourselves in a similar situation, the survival instinct will trigger the startle warning.
If we then recall what happened before as it is brought to mind and again feel those same negative emotions, then we are reinforcing the warning and the phobia is starting to develop. If on the other hand we get the reminder but dismiss it as not relevant now, the survival instinct is switched off and the phobia fails to grow.
Often, if someone has actually fallen from a high place they will have been injured. It would then only be sensible for their survival instinct to try and stop them from repeating the experience.
In some circumstances it is in our own best interests to develop what we call a 'healthy fear'. This is a fear as the result of having done something potentially dangerous and being harmed in the process
There are, however, those who fall from a height and injure themselves when doing something they enjoy. When they recover and attempt to return to the same activity they will get a startle warning from their survival instincts. They will choose to disregard this warning and do it anyway.
An example might be someone who fell from a height whilst skiing or rock climbing. We can all name people who, despite having had accidents whilst doing their chosen sport, return to do the same things again. Very often these people get a certain thrill from putting themselves in danger.
We each have to draw our own line between extreme safety and an acceptable degree of risk in order to feel alive. There would be little point in a life spent in total safety in a secure bubble yet this option often seems attractive to those who are experiencing a degree of anxiety that they are unable to cope with.
A phobia will only develop when and where we allow it to. If we decide it would interfere with something we really want to do, then we choose to disregard the warnings.
We can develop a phobia without having had a particularly bad experience. If someone climbs a ladder and decides they don't like the feeling of being high up and allows themselves the experience negative arousal (fear), then this tells the survival instinct that being in such high places is probably dangerous so on the next occasion it will try and warn of the danger with more raised negative arousal - and so the fear of heights develops further.
To overcome an excessive fear of high places it is necessary to train yourself to not entertain the scary thoughts. Presumably you have no choice but to be in that situation so there is no point fighting the fact. Far better to accept where you are but to put your mind onto other things, such as a Calm Scene and let the body go Dead Weight. That way the fear response will not increase to uncomfortable levels and you will effectively be teaching the survival instinct that this situation is not really life-threatening.