Fear one, fear them all: A systematic review and meta-analysis of fear generalization in pathological anxiety

Neurosci Biobehav Rev. 2022 Aug:139:104707. doi: 10.1016/j.neubiorev.2022.104707. Epub 2022 May 25.


It is a defining feature of anxiety disorders that fear is elicited by a circumscribed class of stimuli rather than by only one specific exemplar of that class. Therefore, fear generalization, a mechanism by which associative fear extends from one conditioned stimulus to similar cues, has been central to theories on anxiety. Yet, experimental evidence for the link between generalization and pathological anxiety, as well as its moderators, has not been formally integrated. This systematic review and meta-analysis of empirical findings clarifies the relationship between fear generalization and pathological anxiety. In conclusion, enhanced fear generalization is associated with several anxiety disorders and stress-related disorders, which is supported statistically by a small, but robust effect size of g = 0.44 for risk ratings as an index of fear generalization. However, empirical results are inconsistent across disorders and they rarely allow for conclusions on their causality in the disorders' etiology. Therefore, based on theoretical considerations, we recommend directions for intensified research, especially on the causal relationship between overgeneralization and pathological fear.

Keywords: Etiology of anxiety disorders; Fear generalization; Meta-analysis; Overgeneralization of fear; Pathological anxiety; Systematic review.

Publication types

  • Meta-Analysis
  • Review
  • Systematic Review
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anxiety
  • Anxiety Disorders
  • Conditioning, Classical
  • Fear*
  • Generalization, Psychological*
  • Humans