Abstract
Fear of heights is common, appears early in life and occurs in many land dwelling animals throughout the phylogentic scale (including chicks, goats, lambs, dogs, pigs, cats, turtles and neonatal monkeys). Theories that fear results from previous traumatic experiences (i.e. conditioning models of fear acquisition) have enjoyed widespread support for over half a century. Recent research, however, has cast doubt on the validity of these models. A small number of retrospective studies on the etiology of height fear have obtained findings consistent with an inherited (non-experiential) explanation of fear acquisition. Unfortunately, there are a number of methodological weaknesses that limit the conclusions that can be drawn from these studies (e.g. reliance on imperfect memory to recall events many years earlier).
The present investigation attempts to overcome these methodological shortcomings by examining the relationship between putative conditioning events before age 9, and the presence of height fear at age 11 and 18 in a longitudinal birth cohort. In this study, fear of heights at age 11 was defined as self-reported avoidance behaviour in relation to height situations. Fear of heights at age 18 was defined as self-report of extreme nervousness or panic on approach to the feared situation. If individuals also reported interference with social or work activities, their height fear was designated "severe". Traumatic conditioning events involving heights were defined as falls from one level to another resulting in fracture, dislocation, intracranial injury or laceration. For the purposes of analysis, falls were divided into two groups; those occurring between 0-5 years and those occurring between 5-9 years. No positive relationship was found between a history of falls before the age of 9 and fear of heights at age 11 and 18. Interestingly, falls resulting in injury between age 5-9 years occurred more frequently in those without a fear of heights at age 18 (t=5.45, p<0.01) - a finding in the opposite direction to that predicted by conditioning theory. In general, these results are consistent with non-associative theories of fear acquisition. Further, it appears that conditioning experiences during critical developmental periods may actually protect against the development of fear.