Failure to overcome 'innate' fear: a developmental test of the non-associative model of fear acquisition

The non-associative, Darwinian theory of fear acquisition proposes that som e individuals fail to overcome biologically-relevant fears (e.g. height) be cause they (1) do not have sufficient safe exposure to the relevant stimuli early in life or (2) are poor habituators who have difficulty "learning no t to fear'. These two hypotheses were tested in a longitudinal birth cohort study. Study 1 found evidence for reduced exposure to height stimuli in ch ildhood for individuals with a fear of heights compared to study members wi thout fear. Study 2 found evidence for higher levels of stress reactivity ( a proxy for habituation) in childhood and adolescence among 18-year-old hei ght phobics compared to study members with dental phobia and those with no fear. The results were discussed in relation to recent findings suggesting that some evolutionary-relevant fears may appear in the absence of traumati c 'learning' experiences. The merits of adding a fourth, non-associative pa thway to Rachman's [Rachman, S. (1977)]. The conditioning theory of fear ac quisition: a critical examination. Behaviour Research and Therapy, 15, 375- 387) three pathways model of fear acquisition were briefly considered. (C) 2000 Elsevier Science Ltd. All rights reserved.