To Freeze or Flee? How The Body And Mind Reacts To A Stressor
Christopher Philip

Much has been written in the nonverbal literature suggesting that bodies might freeze when facing particularly disturbing emotional situations. It’s been said that the hands and feet in particular will decrease in their movement indicating underlying feelings of threat.

“Specifically,” say the researchers “freezing—or tonic immobility—may overwhelm other competing action tendencies. For example, when fleeing or aggressive responses are likely to be ineffective, a freeze response may take place.”

Freezing may also have adaptive advantages. For example, many animals “play dead” when facing predatory attack. This might seem counterintuitive as a strategy, however,
”tonic immobility” might be the best response when escaping or winning a fight is unlikely. During conflict, playing dead might have a predator release an animal from it’s jaws, if only long enough to escape, or lack of moment might prevent a predatory response altogether. Predatory fish such as large pike, for example, will attack a moving metal fishing lure shaped into a spoon that darts and weaves through the water column. One that lays on the bottom, will go unnoticed.

Freeze responses have been noted in the case of rape and also in panic disorders as well as PTSD.

Toward studying this further a team of researchers led by Norman B. Schmidt, Department of Psychology, Florida State University, set subjects up with a stress event to measure their reactions.

The study was simple in that a non-clinical set of human subjects (not suffering from anxiety) underwent a 20-second 20% CO2/balance O2 challenge. They were then measured on various dimensions.

It was found that 13% of the sample reported perceptions of immobility or freezing and 20% reported a desire to flee. Levels of panic and anxiety during the challenge were associated with the desire to flee.

The data finds that there is great variation in the level of immobility suggesting that not all people react in the same way to stress as others. Also, panic and a significant desire to flee was also closely linked to perceptions of immobility.

The data is interesting and provide a framework to examine how exactly a person might respond to outside stress and how this might become apparent in a persons body language. It may be the case that while some might show outer symptoms to stress through limiting movement, others might not react to stress in the same way. More research is necessary before we can reach certain conclusions.


Schmidta, Norman B.; J. Anthony Richey; Michael J. Zvolensky and Jon K. Maner. Exploring human freeze responses to a threat stressor. Journal of Behavior Therapy
and Experimental Psychiatry. 2008. 39: 292-304.