A common reaction women have while being raped serves as a barrier to prosecution and conviction because the criminal justice system and jurors don't understand the phenomenon or the brain science behind it, the New York Times Magazine reports. Known as tonic immobility, or more commonly described as mentally "freezing" during an attack, this natural response to trauma — the opposite of the "fight or flight" response that's better known — often gets misinterpreted as consent. Tonic immobility is a survival strategy common to many classes of animals in which the victim is left paralyzed, unable to move or speak. Studies dating back decades have suggested it is common in sexual abuse. “If we can understand how our brain responds to threat or attack, we can help validate victims’ responses to and memories of sexual assault with the credibility of science," said Jim Hopper, a clinical psychologist and teaching associate at Harvard Medical School, has studied trauma and sexual assault, including their neurobiological aspects, for more than 30 years.
In one 2012 study of more than 12 years' worth of data on sexual-assault cases that had fallen out of the criminal justice system, police regularly dismissed rape reports because they didn’t understand common physiological responses to trauma and assumed victims were lying. Hopper is among a growing group of experts now providing training to police, prosecutors, campus investigators and administrators, and major organizations like the U.S. military, to help them interact better with rape victims and to explain possible reasons for a victim's passive response or memory lapses. Catrina Weigel, a deputy district attorney in Boulder County, Colo., said defense attorneys often cross-examine victims by noting that “they didn’t fight the person — how they didn’t kick, didn’t bite, didn’t scream.” She must rely on experts like Veronique Valliere to help explain a victim’s response. A forensic psychologist, Valliere is often called to help explain to judges and jurors why victims don’t resist or try to escape — including in high-profile cases like Bill Cosby’s trial for rape. “We need to understand that freezing is involuntary, from a medical and scientific perspective, to change the perception that it is a failure of agency,” she said. “In terms of volition, tonic immobility is no different than having a severed spinal cord, and that will help take away the stigma, socially and legally.”