Psychologists Richie Poulton, Simon Davies, Ross G. Menzies, John D. Langley, and Phil A. Silva sampled subjects from the Dunedin Multidisciplinary Health and Development Study who had been injured in a fall between the ages of 5 and 9, compared them to children who had no similar injury, and found that at age 18, acrophobia was present in only 2 percent of the subjects who had an injurious fall but was present among 7 percent of subjects who had no injurious fall (with the same sample finding that typical basophobia was 7 times less common in subjects at age 18 who had injurious falls as children than subjects that did not).More studies have suggested a possible explanation for acrophobia is that it emerges through accumulation of non-traumatic experiences of falling that are not memorable but can influence behaviours in the future. Also, fear of heights may be acquired when infants learn to crawl. If they fell, they would learn the concepts about surfaces, posture, balance, and movement. Cognitive factors may also contribute to the development of acrophobia. People tend to wrongly interpret visuo-vestibular discrepancies as dizziness and nausea and associate them with a forthcoming fall. A traumatic conditional event of falling may not be necessary at this point. A fear of falling, along with a fear of loud noises, is one of the most commonly suggested inborn or "non-associative" fears. The newer non-association theory is that a fear of heights is an evolved adaptation to a world where falls posed a significant danger.
The human balance system integrates proprioceptive, vestibular and nearby visual cues to reckon position and motion. As height increases, visual cues recede and balance becomes poorer even in normal people. However, most people respond by shifting to more reliance on the proprioceptive and vestibular branches of the equilibrium system. Some people are known to be more dependent on visual signals than others. People who rely more on visual cues to control body movements are less physically stable. An acrophobic, however, continues to over-rely on visual signals whether because of inadequate vestibular function or incorrect strategy. Locomotion at a high elevation requires more than normal visual processing. The visual cortex becomes overloaded, resulting in confusion. Some proponents of the alternative view of acrophobia warn that it may be ill-advised to encourage acrophobics to expose themselves to height without first resolving the vestibular issues. Research is underway at several clinics. Recent studies found that participants experienced increased anxiety not only during elevation in height, but also when they were required to move sideways in a fixed height.A recombinant model of the development of acrophobia is very possible, in which learning factors, cognitive factors (e.g. interpretations), perceptual factors (e.g. visual dependence), and biological factors (e.g. heredity) interact to provoke fear or habituation. Assessment
ICD-10 and DSM-5 are used to diagnose acrophobia. Acrophobia Questionnaire (AQ) is a self report that contains 40 items, assessing anxiety level on a 0–6 point scale and degree of avoidance on a 0–2 point scale.