Exploring human freeze responses to a threat stressor

J Behav Ther Exp Psychiatry. 2008 Sep;39(3):292-304. doi: 10.1016/j.jbtep.2007.08.002. Epub 2007 Aug 12.


Despite the fundamental nature of tonic immobility in anxiety responses, surprisingly little empirical research has focused on the "freeze" response in humans. The present report evaluated the frequency and predictors of a freeze response in the context of a biological challenge. A nonclinical sample (N=404) underwent a 20-s inhalation of 20% CO(2)/balance O(2). Perceptions of immobility in the context of the challenge were reported in 13% of the sample, compared with 20% reporting a significant desire to flee. Subjective anxiety and panic during the challenge were associated with the freeze response, as were a number of anxiety symptom dimensions.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Anxiety Disorders / diagnosis*
  • Anxiety Disorders / physiopathology
  • Anxiety Disorders / psychology
  • Awareness / physiology
  • Carbon Dioxide
  • Causality
  • Diagnostic and Statistical Manual of Mental Disorders
  • Fear / physiology
  • Female
  • Freezing Reaction, Cataleptic / physiology*
  • Humans
  • Life Change Events*
  • Linear Models
  • Longitudinal Studies
  • Male
  • Models, Psychological
  • Panic Disorder / diagnosis
  • Panic Disorder / physiopathology
  • Panic Disorder / psychology
  • Personality Inventory
  • Probability
  • Psychiatric Status Rating Scales
  • Severity of Illness Index
  • Surveys and Questionnaires


  • Carbon Dioxide