Why Many Sexual Assault Survivors Can't "Fight Back"

When it comes to sexual assault, people often seem to assume that it's easy enough for survivors to just fight back, or somehow try to overpower and escape their attackers. But one new study provides some evidence as to why that's not always possible.

The study, published in Acta Obstetricia et Gynecologica Scandinavica, found that most sexual assault survivors "freeze up" during the assault, experiencing a temporary involuntary paralysis, known as tonic immobility.

According to the study tonic immobility as "an 'involuntary, temporary motor inhibition' when exposed to extreme threat," is believed to be a response to attack that occurs when there seem to be no other options to avoid it.

For the research, Anna Möller, MD, PhD, of the Karolinksa Institute and the Stockholm South General Hospital in Sweden, and her colleagues studied the cases of 298 women who visited the Emergency Clinic for Rape Victims in Stockholm within one month of a sexual assault.

Of those women, about 70% reported significant tonic immobility and 48% reported extreme tonic immobility during the assault. What's more, among the 189 women who completed a 6-month assessment, 38% had developed PTSD and 22% developed severe depression. Those who experienced tonic immobility were associated with increased risk of developing PTSD and severe depression.

The researchers said they hoped that the study will help us better understand how assault can affect survivors.

"The present study shows that tonic immobility is more common than earlier described," Dr. Möller said in a statement shared with Refinery29. “This information is useful both in legal situations and in the psychoeducation of rape victims. Further, this knowledge can be applied in the education of medical students and law students.”