14 DAY TRIAL // People who are afraid of heights actually suffer from deformed vertical perception, which doesn't allow them to correctly appreciate the distance between themselves and the ground. The condition, which is known as acrophobia and is often mislabeled “vertigo,” makes individuals think that distances are larger than what they actually measure.
In other words, the stronger the fear, the more height people suffering from acrophobia perceive. The condition can become very serious and affects individuals while performing simple tasks such as driving over a bridge, or taking the elevator to the upper floors of a skyscraper.
The new theory comes to directly contradict already-established hypotheses, which say that “Acrophobia is an excessive fear in response to something that's perceived normally.” The new research holds that perception is the one to blame for this condition, and not other parts of the brain involved in elaborating fear responses.
“An important component of acrophobia appears to be that they are perceiving something different in the first place,” cognitive psychologist Russell Jackson from the California State University in San Marcos, who has led one of the studies supporting the new claim, says.
To test his tentative explanation, the scientist asked 43 students to participate in some tests, after filling a few questionnaires, aimed at gouging their levels of acrophobia. They were then taken to a five-level parking lot, which measured 14.4 meters (48 feet) in height, and asked to assess its dimension both from the ground and from the top of the building. Except for one student, all provided fairly accurate estimates.
But the one that didn't, who later turned out to be an acrophobiac, said that the parking lot was 3 meters higher than what it actually measured, when viewing it from the ground. But when he looked from the 5th floor, he overestimated the structure by more than 12 meters (37 feet). That's almost twice the size of the actual construction, which for Jackson proved that perception was, indeed, the dominant factor in such judgment calls, and not other factors.