Tonic immobility: Study shows why rape victims can't just fight back

Most people who have never been victims of rape think that if they ever found themselves in the horrid situation of being attacked by a sexual predator, they’d fight back.

We assume our survival instincts will kick in.

But if you listen to the experiences of rape victims, it becomes clear that it’s not that simple - many women (for it is nearly always women) find themselves seemingly paralysed, incapable of trying to defend themselves against their attacker.

And a new study from the Karolinksa Institutet and the Stockholm South General Hospital in Sweden has confirmed this - according to the research, the majority of rape victims find themselves involuntarily unable to move, which “blocks” physical resistance.

It’s called “tonic immobility” - described as “an involuntary, temporary state of motor inhibition in response to situations involving intense fear” - and could be a game-changer when it comes to how rape victims are treated in hospitals and court.

“The courts may be inclined to dismiss the notion of rape [if] the victim didn't appear to resist,” study lead author Dr. Anna Möller told Broadly.

“Instead, what might be interpreted as passive consent is very likely to represent normal and expected biological reactions to an overwhelming threat.”

She believes tonic immobility “should be routinely assessed in all sexual assault victims.”

What’s more, the researchers found that tonic immobility was more likely to result in the victim developing post-traumatic stress disorder (PTSD) or severe depression afterwards.

Dr Möller and her team studied 298 women who had visited the Emergency Clinic for Rape Victims in Stockholm within one month of a sexual assault.

70 per cent of the participants reported significant tonic immobility during the assault, and 48 per cent reported extreme tonic immobility.

Six months after the attack, 189 of the women were assessed for the development of PTSD and depression.

Of these women, 38.1 per cent had developed PTSD and 22.2 per cent had developed severe depression.

The researchers concluded that tonic immobility resulted in a 2.75-times increased risk of developing PTSD and a 3.42-times increased risk of developing severe depression.

However they found that tonic immobility is also linked to prior trauma and previous psychiatric treatment.

“The present study shows that tonic immobility is more common than earlier described,” said Dr. Möller.

“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.”