فرآیندهای ضدخوگیری در هراس از ارتفاع و ترس از دندانپزشکی: آزمون غیرمستقیم مدل های غیرارتباطی ترس اکتسابی

The fear dishabituation hypothesis described in the non-associative model of fear acquisition was tested in a longitudinal birth cohort study. Results were consistent with height fear and phobia dishabituation. That is, ‘re-emergence’ of a fear of heights occurred between age 11 and 18 years among individuals who reported higher levels of non-specific stress at age 15. Interestingly, there was no evidence for dental fear dishabituation — a finding consistent with the non-associative model of fear acquisition. Strengths and weaknesses of the study were considered and the results discussed in relation to laboratory-based findings on (dis)habituation.

The non-associative model of fear acquisition maintains that certain cues (e.g. heights, separation) signaled a threat to human survival in pre-technical times. These cues are said to be pre-potent and can manifest at a young age in the absence of aversive conditioning experience (Rachman, 1978, Gray, 1982, Marks and Nesse, 1994 and Menzies and Clarke, 1995a). It has been hypothesised that over time most individuals will grow out of these developmental fears via habituation processes providing they have sufficient safe exposure to the relevant stimuli. However, this does not occur in all cases. Specifically, poor habituators and those who do not have the opportunity for safe exposure are expected to retain their fear which, if persistent, may result in specific phobias in adulthood (Clarke & Jackson, 1983). Additionally, it was hypothesised that non-specific stress may lead to the return of previously habituated fear (Menzies & Clarke, 1995a; also see Jacobs & Nadel, 1985). These three mechanisms have been proposed to explain why not all adults report specific phobias. However, no data exist to support the two habituation hypotheses proposed by Clarke and Jackson (Merckelbach & de Jong, 1997) and only anecdotal evidence is available to support the fear dishabituation hypothesis proposed by Menzies and Clarke (1995a) (e.g. Harris & Menzies, 1996; also see Rachman, 1990).