The ‘Freeze’ Response to Sexual Violence
by the Ending Violence Association of BC
What is Tonic Immobility?
Many survivors describe having felt unable to move or speak during a sexual assault. This temporary state of paralysis, sometimes called the ‘freeze’ response, is also known as ‘tonic immobility.’ Tonic immobility is a physiological response to an intense threat, caused by cortisol and other stress hormones flooding through the body.
What might be interpreted as passive consent is very likely to represent normal and expected biological reactions to an overwhelming threat. 
Dr. Anna Möller
Compared with other types of trauma (e.g., war, motor vehicle accidents), tonic immobility is more frequent and severe in cases of (childhood and adult) sexual violence . For survivors of sexual violence, tonic immobility is “an involuntary response to an inescapable threat” . Women are also more likely to experience tonic immobility during a sexual assault if they have a previous history of sexual violence, in childhood or adulthood. 
A survivor who does not outwardly appear to resist a perpetrator by physically fighting, saying ‘no,’ and/or yelling for help will often be judged by friends, family, and systems responders (e.g., justice system, health services) who lack training on trauma. Survivors who experience tonic immobility may experience more victim-blaming when disclosing and/or reporting sexual violence. Survivors may also be more likely to blame themselves for not actively, outwardly resisting.
Following this particular kind of trauma, survivors who experienced tonic immobility also have poorer mental health. They are twice as likely to experience post-traumatic stress symptoms, and three times more likely to experience severe depression. 
Understanding ‘freeze’ responses can be helpful for survivors who are trying to make sense of what happened to them. It is also useful for individuals offering support, including counsellors.
Recognizing tonic immobility as a common, biologically-based, involuntary reaction to trauma can assist counsellors in providing trauma-informed care for sexual violence survivors.
How Common is Tonic Immobility?
It is very common for survivors of sexual assault to experience tonic immobility. A recent study with 298 research participants found that 70% of survivors experienced tonic immobility. 
Thinking About ‘Protective’ Responses
Sexual violence survivors are often expected to have actively, outwardly resisted a perpetrator – for example, by shouting for help or physically resisting. When survivors do not resist in these ways, their behaviour is usually not seen as ‘self-protective’.
Recent research looking at sexual assaults perpetrated by strangers has challenged this traditional framework; it shows that tonic immobility may actually serve a protective function for sexual assault survivors.  When a survivor becomes verbally and/or physically ‘frozen’, the perpetrator may not need to use as much physical force, resulting in the survivor having fewer and/or less severe injuries.
Because they [sexual assault survivors] had this [tonic immobility] reaction, they’re afraid of how it’s going to be perceived by others, so they’re very reluctant to seek help. And when they do come for help, it’s always there in the back of their mind. They are dreading that question ‘What did you do?’ Because their answer is one that they don’t think anybody’s going to understand and quite frankly they don’t understand, because their answer is ‘I did nothing. I couldn’t do anything. I just laid there.’ 
Dr. Rebecca Campbell
It is important to listen for and normalize survivors’ experiences of ‘freezing’ or tonic immobility. Anti-violence workers, and especially counsellors, should be able to provide a simple, concise explanation of how sexual violence trauma impacts the body and the brain so that survivors are able to understand ‘freeze’ responses as a result of the flooding of hormones, which is out of their control.
Realizing how common tonic immobility is can be reassuring to survivors who may be questioning, or blaming themselves for, their reactions. This knowledge of tonic immobility and sexual assault can also assist with advocacy within the legal system; that is, the appearance of passiveness/silence should not be considered consent, and less emphasis should be placed on physical injuries.
Increased knowledge about sexual violence trauma and tonic immobility can promote more trauma-informed support for survivors.
Ending Violence Association of BC is proud to present their upcoming Annual Training Forum: Advancing Safety Through Connection and Community and AGM. If you are interested in learning more about working with survivors of sexual trauma, please do not miss this event.
Keynote Speakers include:
- Deputy Commissioner Brenda Butterworth-Carr, Commanding Officer, RCMP “E” Division
- Jan Ference – Early Attachment and the Neurobiological Impact of Trauma, Violence and Neglect
- Child and Youth Advocacy Centres Plenary Panel – A Multi-Disciplinary Response to Violence Against Children and Youth
- Vikki Reynolds – Justice-Doing with Each Other: Working with Our Colleagues with Dignity and Respect
Workshop themes this year include:
- Trauma Experienced by Indigenous Peoples
- Resisting Burnout
- Supporting Adult Survivors of Childhood Sexual Abuse
- Third Party Reporting
- Trauma, Neglect, Violence and Brain Development
- Queer- and Trans-Inclusive Anti-Violence Services
- Responses to Women with Disabilities and Deaf Women
For more information and to register for this event please visit www.endingviolence.org
References Möller, A., Söndergaard, H. P., & Helström, L. (2017). Tonic immobility during sexual assault: A common reaction predicting post-traumatic stress disorder and severe depression. Acta Obstetricia et Gynecologica Scandinavica, 96(8), p. 937.  Kalaf, J., Coutinho, E. S. F., Vilete, L. M. P., Luz, M. P., Berger, W., Mendlowicz, M., Volchan, E., Andreoli, S. B., Quintana, M. I., Mari, J. J. & Figueira, I. (2017). Sexual trauma is more strongly associated with tonic immobility than other types of trauma: A population based study. Journal of Affective Disorders, 215, 71–76.  Shors, T. J. & Millon, E. M. (2016). Sexual trauma and the female brain. Frontiers in Neuroendocrinology, 41, p. 88.  Möller, A., Söndergaard, H. P., & Helström, L. (2017). Tonic immobility during sexual assault: A common reaction predicting post-traumatic stress disorder and severe depression. Acta Obstetricia et Gynecologica Scandinavica, 96(8), 901–1030.  Möller, A., Söndergaard, H. P., & Helström, L. (2017). Tonic immobility during sexual assault: A common reaction predicting post-traumatic stress disorder and severe depression. Acta Obstetricia et Gynecologica Scandinavica, 96(8), 901–1030.  Möller, A., Söndergaard, H. P., & Helström, L. (2017). Tonic immobility during sexual assault: A common reaction predicting post-traumatic stress disorder and severe depression. Acta Obstetricia et Gynecologica Scandinavica, 96(8), 901–1030.  de Heer, B. A. & Jones, L. C. (2017). Investigating the self-protective potential of immobility in victims of rape. Violence and Victims, 32(2), 210–229.  Campbell, R. (2012). The Neurobiology of Sexual Assault. (Presentation). National Institute of Justice. https://nij.gov/multimedia/presenter/presenter-campbell/Pages/presenter-campbell-transcript.aspx