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Your Stone Age Brain

Your Stone Age Brain is an information handout which describes the freeze-flight-fight response: a set of evolutionary adaptations that increase the chances of survival in threatening situations. The ‘hardware’ underlying these responses in modern humans is thought to be unchanged in the last 200,000 years, and psychologists often use a ‘caveman metaphor’ to explain the purpose and function of these responses. Learning about some of the evolutionary pressures exerted on early modern humans helps clients to understand the consequences of living in the present day in a body that has the same ‘programming’.

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Introduction & Theoretical Background

The freeze-flight-fight response is a set of evolutionary adaptations that increase the chances of survival in threatening situations. Consciously or unconsciously appraising an event as dangerous triggers an automatic defense cascade of physiological and cognitive responses that prepare the individual to freeze, flee, or fight (Bracha et al, 2004; Kozlowska et al, 2015). These responses are present in many other species (Canon, 1929), and the ‘hardware’ underlying them in modern humans is thought to be unchanged in the last 200,000 years (Nitecki & Nitecki, 1994). Psychologists often use the ‘Caveman metaphor’ to illustrate how ingrained these responses are. 

Freeze-flight-fight responses are associated with activity in the autonomic nervous system (ANS). Fight and flight are supported by increased activity in the sympathetic branch of the ANS, which increases heart rate, blood pressure, respiration, and muscle tone, and inhibits digestive function. Freezing is associated with activity in both the sympathetic and parasympathetic branches of the ANS (Roelofs, 2017). 

An overly sensitive freeze-flight-fight response can be a key part of multiple anxiety disorders, resulting in overly frequent or intense experiences of anxiety (Andrews et al, 2003). The clearest example is panic: the cognitive model of panic suggests that misinterpreting benign body symptoms as a threat leads to activation of the freeze-flight-fight system, and often exacerbates the body sensations about which the individual is concerned (Clark, 1996).

Important elements of psychoeducation for anxious clients include helping them to understand:

  • Why people have a threat-detection system which is ‘programmed’ to respond with freeze-flight-fight.
  • What kinds of threats that this system is designed to detect (e.g. physiological threats such as cold & hunger, physical threats such as attack, social threats such as exclusion or changes in social status).
  • That freeze-flight-fight reactions, although sometimes uncomfortable, are not dangerous.
  • That these reactions and feelings are often automatic, not the person’s fault, and nothing to be ashamed of.
  • That the freeze-flight-fight response has a bias toward caution: it would rather set off a false alarm than miss a real danger.
  • The threat detection system can fail to distinguish between real threats ‘out there’ in the world vs. imagined threats.

Your Stone Age Brain is an information handout which describes some of the evolutionary pressures exerted on early modern humans. It explains why a well-developed freeze-flight-fight system helped our ancestors to survive, and the consequences of living in the present day in a body that has the same ‘programming’. It also describes some of the negative consequences of living with a sensitive threat detection system.

Therapist Guidance

Did you know that what we feel anxious about, and the way we feel anxious in our bodies and minds, has to do with our Stone Age ancestors? Would you be willing to explore this with me? 

Review the types of situations that our ancestors found threatening. These include physiological threats (e.g. cold, hunger, thirst), physical threats (e.g. attack, capture), and social threats (e.g. threat to social rank, exclusion from the group). After reviewing them, consider asking:

  • What would have happened to Stone Age people that didn’t notice these kinds of dangers?
  • Are you ever bothered by any of the same threats?
  • What kinds of body / physical / social threats bother you?
  • Do you ever feel concerned about any of these things?
  • What do you feel in your body when you encounter threats?
  • Can you tell me about a time when you thought you were in danger? What did you notice? What was going through your mind? What did you feel in your body?

Review the automatic ways in which our ‘programming’ helps us to behave when we feel threatened. These include freezing or hiding, fleeing or escaping, and fighting or acting aggressively. After reviewing these types of situations, consider asking:

  • If a person or animal was in danger, why might it be helpful for them to react by freezing / escaping / fighting?
  • If you encountered a dangerous animal, why might it be a good idea to back off or run away?
  • Have you ever reacted to a danger by freezing, escaping, or becoming aggressive? Tell me about it.
  • Could you tell me about any of your reactions that are similar?
  • When you react in these ways, what are you feeling in your body and mind?

Review ways in which having a threat detection system has negative consequences:

  • Have you ever had a freeze-flight-fight reaction in a situation that wasn’t really dangerous?
  • Sometimes people liken their freeze-flight-fight reaction to an over-sensitive smoke alarm or car alarm. Do you think yours is like that sometimes?
  • Do you ever feel anxious when you are just thinking about something that worries or scares you? What reactions do you notice in your body?

References And Further Reading

  • Andrews, G., Creamer, M., Crino, R., Page, A., Hunt, C., & Lampe, L. (2003). The treatment of anxiety disorders: Clinician guides and patient manuals. Cambridge University Press.
  • Bracha, S., Williams, A. E., & Bracha, A. S. (2004). Does” fight or flight” need updating?. Psychosomatics, 45(5), 448-449.
  • Cannon, W.B. (1929). Bodily Changes in Pain, Hunger, Fear and Rage: An Account of Recent Research Into the Function of Emotional Excitement. New York: Appleton-Century-Crofts.
  • Clark, D. M. (1986). A cognitive approach to panic. Behaviour Research and Therapy, 24(4), 461-470.
  • Kozlowska, K., Walker, P., McLean, L., & Carrive, P. (2015). Fear and the Defense Cascade. Harvard Review of Psychiatry, 23(4), 263–287.
  • Nitecki, M. H., Nitecki, D. V. (1994). Origins of anatomically modern humans. New York: Plenum Press.
  • Roelofs, K. (2017). Freeze for action: neurobiological mechanisms in animal and human freezing. Philosophical Transactions of the Royal Society B: Biological Sciences, 372(1718), 20160206.