This is the second story in a three-part series examining how the rules governing sexual-assault adjudication have changed in recent years, and why some of those changes are problematic. Read the first installment here, and the third one here.

As debate has begun over whether the rules governing sexual-assault adjudication have gone too far, one subject has received almost no attention, although it has become central to the way that many schools and many activists view sexual assault. In the past few years, the federal government has required that all institutions of higher education train staff on the effects of “neurobiological change” in victims of sexual assault, so that officials are able to conduct “trauma informed” investigations and adjudications.

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In meeting this federal demand, some schools have come to rely on the work of a small band of self-styled experts in the neurobiology of trauma who claim that sexual violations provoke a disabling, multifaceted physiological response. Being assaulted is traumatic, and no one should expect those who have been assaulted to have perfect recall or behave perfectly rationally, but this argument goes much further. It generally goes like this: People facing sexual assault become terrified, triggering a potent cascade of neurotransmitters and stress hormones. This chemical flood impairs the prefrontal cortex of the brain, impeding victims’ capacity for rational thought, and interferes with their memory. They may have significant trouble recalling their assault or describing it coherently or chronologically. The fear of imminent death may further elicit an extended catatonic state known as “tonic immobility,” rendering them powerless to speak or move—they feel “frozen.”

As a result, those adjudicating sexual-assault allegations are told, the absence of verbal or physical resistance, the inability to recall crucial parts of an alleged assault, a changing story—none of these factors should raise questions or doubt about a claim. Indeed, all of these behaviors can be considered evidence that an assault occurred.

“I don’t think I’ve seen a complaint in the past year that didn’t use the word frozen somewhere.”

Rebecca Campbell, a professor of psychology at Michigan State University, has taught the science of trauma to law-enforcement officials and Title IX administrators. In 2015, she gave a keynote talk at the Association of Title IX Administrators’ annual conference, about how the neurobiology of trauma could be used in their investigations. A highly influential presentation she gave in 2012 at the National Institute of Justice, “The Neurobiology of Sexual Assault,” has been used as part of some schools’ Title IX–personnel training.

In her 2012 talk, Campbell acknowledged that she is not a neuroscientist, but rather is translating others’ work. (Campbell’s own scholarly work has involved community-based research into how contact with the legal and medical systems affects assault victims’ psychological and physical health, and research into the use of rape kits.) She asserted that the damaged memory of a victim can be likened to “tiny Post-it notes” scattered randomly across “the world’s messiest desk.” For a sexual-assault victim to reconstruct what happened requires a sympathetic questioner who will give the victim the time and space to reassemble the Post-its in a coherent order. She assured her audience that the story that emerges will be a true account of the crime: “What we know from the research is that the laying-down of that memory is accurate and the recall of it is accurate.” She briefly recognized that victims who consumed alcohol may have serious memory problems as a result—“their Post-it notes are just blank.” Tonic immobility, she said, is a “mammalian response that is in all of us,” likely affecting close to 50 percent of sexual-assault victims. “Their body freezes on them,” she said, and not just for a moment or two. The victims go into an extended state in which they can’t speak or move, and hence cannot fend off an assailant.

As of 2014, Harvard Law’s Title IX training for its disciplinary board included Campbell’s PowerPoint slides. Janet Halley, a professor at Harvard Law School, has written of the intended effect of the training on recipients: “It is 100% aimed to convince them to believe complainants, precisely when they seem unreliable and incoherent.”

All of these concepts are presented in information distributed to students on many campuses. The University of Michigan’s Sexual Assault Prevention and Awareness Center has a webpage for students on the “Neurobiology of Trauma” based largely on Campbell’s lecture. It explains that as a result of the “hormone soup” provoked by an assault, “the survivor cannot move and is rendered immobile by the traumatic event,” and “survivors may have trouble accurately remembering the assault.” Bowdoin College’s Title IX webpage on “The Neurobiology of Sexual Assault,” also based on Campbell’s lecture, tells students that “the flood of hormones can even, and often does, result in a complete shutdown of bodily function, a state referred to as ‘tonic immobility,’ but better described as paralysis” and that victims “also may exhibit fragmented memory recall due to the disorganized encoding that occurred during the incident.”

This information sends the message to young people that they are biologically programmed to become helpless during unwanted sexual encounters and to suffer mental impairment afterward. And it may inadvertently encourage them to view consensual late-night, alcohol-fueled encounters that might produce disjointed memories and some regret as something more sinister.

Justin Dillon, a Washington, D.C., attorney who defends students across the country accused of Title IX violations, told me that a couple of years ago he had barely heard of this condition, but that its terminology has swiftly made its way into campus adjudications: “I don’t think I’ve seen a complaint in the past year that didn’t use the word frozen somewhere.” Trauma, he says, is used to explain away all inconsistencies in some complainants’ accounts that would otherwise seem to contradict their having been assaulted. Schools do not make public the training materials of those who investigate and adjudicate sexual assault. But through lawsuits, Dillon has obtained some examples, and he says the assertions of the “neurobiology of trauma” that infuse these materials make it almost impossible for the accused to mount a defense. When such assumptions are held by those sitting in judgment, he says, “how do you prove your innocence?”

“The brain is not a videotape machine. All of our memories are reconstructed.”

Various initiatives have spread ideas about this syndrome out into the collegiate world. In 2013, funding from the federal government established the National Center for Campus Public Safety, an educational resource for campus administrators that offers a “Trauma-Informed Sexual Assault Investigation and Adjudication” curriculum, and purveys the ideas popularized by Campbell and others. Last year, the University of Texas at Austin released a state-funded report, “The Blueprint for Campus Police: Responding to Sexual Assault,” with the hope of it becoming a national model. It codified “victim-centered and trauma-informed” investigations, asserting: “Trauma victims often omit, exaggerate, or make up information when trying to make sense of what happened to them or to fill gaps in memory.” And “due to the neurobiology of trauma, victims may suffer from a rape-induced paralysis called tonic immobility.” In 2015, Illinois passed the Preventing Sexual Violence in Higher Education Act, which demanded that campus personnel receive “training centered on the neurobiological impact of trauma”; other states are considering similar legislation.

I talked with Richard McNally, a psychology professor at Harvard and one of the country’s leading experts on the effects that trauma has on memory, about the assertions Campbell made in her presentation. He first said that because assaults do not occur within the laboratory, “there is no direct evidence” of any precise or particular cascade of physiological effects during one, “nor is there going to be.” But there is plenty of evidence about how highly stressful experiences affect memory, and much of it directly contradicts Campbell. In his 2003 book, Remembering Trauma, McNally writes, “Neuroscience research does not support [the] claim that high levels of stress hormones impair memory for traumatic experience.” In fact, it’s almost the opposite: “Extreme stress enhances memory for the central aspects of an overwhelming emotional experience.” There is likely an evolutionary reason for that, McNally said: “It makes sense for natural selection to favor the memory of trauma. If you remember life-threatening situations, you’re more likely to avoid them.” Notably, survivors of recent horrific events—the Aurora movie-theater massacre, the San Bernardino terror attack, the Orlando-nightclub mass murder—have at trial or in interviews given narrative accounts of their ordeals that are chronological, coherent, detailed, and lucid. (In the years since McNally’s book was published, some neuroscientific evaluations of military personnel have indicated that, in conditions of the most extreme stress, these hormones might prevent certain memories from being retained, causing gaps or errors in a person’s recollection. But these findings are different from the assertion that traumatic memories are stored in infallible yet “fragmented” condition.)

Campbell’s claim that a sexual-assault victim’s memory consists of completely accurate but disorganized fragments contradicts fundamental scientific knowledge of the nature of memory, McNally told me. “The brain is not a videotape machine,” he said. “All of our memories are reconstructed. All of our memories are incomplete in that sense.” Each time we recall an event, it is being reassembled, and sometimes changed by the very process of recall.

All the experts I spoke with expressed concern about the malleability of memory, especially when people are being encouraged to clarify murky experiences. A 2015 study by the education insurance group United Educators, examining 305 claims of sexual assault at 104 schools, found that about 40 percent of students delayed reporting an assault (there are many valid reasons why they might do so, including fear of stigma). The average delay was 11 months, and “in most cases, the victim labeled the incident a sexual assault only after talking with friends or attending prevention training.” Elizabeth Loftus, a professor of psychology and social behavior at UC Irvine, has done pathbreaking work on memory manipulation. When I described to her what’s now being taught to administrators and students, she said it sounded disturbingly like a return of “recovered memory” theory, with some neurobiology thrown in “to give luster” to the argument.

During the recovered-memory scare of the 1980s and ’90s, thousands of people were convinced by their therapist—and by best-selling books on the subject—that their problems were caused by repressed memories of childhood sexual abuse, often at the hands of their father. The theory was that the mind buried what had happened because it was so awful, but that the “forgotten” events nonetheless caused a lifetime of pain. Guided by therapists, victims were able to recover the memory and begin healing.

As it turned out, though, many therapists were implanting false memories in vulnerable people, resulting in baseless accusations that tore families apart. The frenzy eventually burned out when researchers, including McNally, discredited the underlying assumptions. “The notion that the mind protects itself by repressing or dissociating memories of trauma,” he writes in Remembering Trauma, “is a piece of psychiatric folklore devoid of convincing empirical support.”

Loftus also talked about the effects of drinking on memory. She said that with alcohol-induced memory fragmentation, attempts to reconstruct events are “very vulnerable to post-event suggestion.” This can include someone, especially an authority figure, labeling a consensual act as rape. She said it’s then easy for exaggerated, or even entirely false, memories to be created, ones that feel completely real. “This is extremely worrisome,” she told me. “The universities are under enormous pressure to do something about sexual assault, and they sometimes fill these offices with people whose bias and agendas lead them to create victimhood.”

Tonic immobility has at least some scientific pedigree. The “playing dead” mechanism of prey animals, particularly those that find themselves literally in the jaws of death, is well documented and likely adaptive; a predator might relax its grip if it believes the prey is dead, increasing the chance of escape. But research on the subject has focused primarily on small animals, notably poultry. (Factory-farm conditions can be frightening to chickens, and episodes of tonic immobility are thought to have deleterious effects on poultry production.)

In the mid-2000s, a few researchers began studying whether tonic immobility occurs in humans. A handful of surveys have asked people who said they had experienced a trauma whether they remembered, for example, feeling paralyzed or unable to call out. Some have said yes, and perhaps they did, but a few researchers have noted potential problems in these retrospective questionnaires, including leading or ambiguous language that might prompt certain responses. In the lab, some researchers have tried to find evidence of the response in people by measuring how much their body moved when they listened to scripts recounting real-life traumas they’d faced, or by confronting them with images of a gun. But because it is ethically unacceptable to create a true sense of life-threatening terror, these experiments are inherently limited, and their findings are far from conclusive.

To be sure, some people do freeze briefly in terrifying circumstances. But in her National Institute of Justice presentation, Campbell used the terms freeze and tonic immobility synonymously. These are two distinct phenomena, well documented in animals. Researchers describe a “freeze” as a momentary state of high alert that occurs before deciding whether and how to act. Charles A. Morgan III, a forensic psychiatrist at the University of New Haven who studies stress response in military personnel, says there’s ample evidence of this response on the part of people. But, he told me, “it’s not people acting like they’re zombies”; they generally return swiftly to responsiveness. Liz Phelps, a professor of psychology and neural science at NYU, concurs. She cited the Atlanta Olympic bombing as an example. A video of the event shows that when the bomb went off, many in the crowd froze. But it was “a momentary freeze before people started running. It’s such a subtle response in humans that it’s very hard to study,” she says.

Tonic immobility might occur in people, but science hasn’t definitively shown this yet. Even if it does occur, we cannot say with any certainty that it affects nearly 50 percent of sexual-assault victims, as Campbell claims is likely in her presentation. Tonic immobility’s frequent precursors in prey animals—physical restraint combined with an imminent threat to life—do describe some instances of rape. But the conditions that lead to many sexual-assault complaints on college campuses—alcohol combined with miscommunication—do not fit this template.

I spoke with Campbell about all of this last fall, and in our conversation, she said the goal of her work on neurobiology was to give law-enforcement officers a more nuanced understanding of how a sexual-trauma victim might behave. Its generalized use as a guide for campus investigations and adjudications—and particularly to support the idea that no matter how a complainant behaves, she is almost certainly telling the truth—was unintended, she said, and “would be an overreach.” But whatever its intent, her talk on fragmented memory and tonic immobility is unsupported by prevailing scientific research and findings. Campbell acknowledged to me that her talk incorrectly conflated freeze and tonic immobility. “That is something in later presentations I’ve learned to correct,” she said. While her lecture conveys certainty and assurance, she told me that we don’t know “as much as we’d like to” about tonic immobility and that there are “very valid questions” as to whether it occurs in humans.

Lawyers for accused students are starting to challenge the way such ideas about trauma may bias campus adjudications. In July, for example, a male student at the University of Oregon, who had been suspended after having been found to have sexually assaulted a female student with whom he’d had a previous sexual relationship, filed a civil suit against the university and three university officials in federal court. According to the complaint, the female student provided inconsistent accounts of the alleged assault—the male student says there was no sexual contact that night—and both electronic evidence and witness statements contradicted her timeline of events. But, the complaint says, the Title IX officer investigating the case concluded that the female student’s “stories shifted because she suffered from trauma-induced memory problems.” The male student appealed his suspension and submitted an expert report from a psychology professor arguing, the complaint says, that the Title IX officer’s assertions about trauma and memory were “not scientifically supportable.” (The suspension had been upheld by the school, but was later overturned by a state judge, who found that the school had conducted an unfair process, in part because the male student had not been allowed to rebut the Title IX officer’s claims about memory in the original proceeding.)

But one-off legal challenges are unlikely to eliminate the erroneous ideas being promulgated on many campuses. The spread of an inaccurate science of trauma is an object lesson in how good intentions can overtake critical thinking, to potentially harmful effect. Many rapes go unreported because the process of reporting them and seeking justice can be miserable for the victim. That the desire to lessen this misery has guided many reforms to campus adjudication is understandable and appropriate—to a point. Campbell’s 2012 lecture sought to persuade police investigators to give victims, in the immediate aftermath of a sexual assault, some space to collect themselves, and to conduct a first interview in a way that’s neutral rather than hostile—laudable, commonsense goals. But commonsense goals, when dressed up by policy makers and victims’ advocates in the inaccurate science now widespread on campus, can be (and have been) easily expanded to serve the idea that virtually every action and behavior that might cast legitimate doubt on an assault should be routinely discounted—and that no matter what precedes or follows an accusation of assault, the accused is always guilty.

The result is not only a system in which some men are wrongly accused and wrongly punished. It is a system vulnerable to substantial backlash. University professors and administrators should understand this. And they, of all people, should identify and call out junk science.