Exciting new research in neuroscience highlights sex differences of the brain at all levels, from structure and function to nervous systems. It is now understood that sex is a significant biological variable in areas beyond reproduction.
It’s a groundbreaking area of neuroscience discovery, and the Sandra Day O’Connor College of Law at Arizona State University is at the forefront of exploring the complex web of legal, ethical and policy implications it creates.
“We know that some brain disorders have sex-biased population differences. For example, in the general population, men have higher rates of autism and ADHD, while women have higher rates of depression and Alzheimer’s disease. The hope is that this research will help with diagnosis and treatment for those disorders. Scientists have also observed population behavioral differences between men and women in areas like emotion, memory, pain perception, spatial processing, facial identification, motor speed — those kinds of behaviors,” said ASU Law Professor Betsy Grey, who specializes in neuroscience and law.
“And for a very long time, neuroscience just assumed that these observed population-based differences in behavior were due to cultural and social factors. Now we are starting to question whether biology may influence those differences as well, as we start discovering these sex-based differences in brain systems. And that may or may not account for some of the behavioral differences. And that’s what is very controversial.”
Leading experts gathering at ASU Law
These sex-based differences in the brain are the latest focus area for ASU Law’s Center for Law, Science and Innovation, which examines emerging neuroscience topics on a two-year rotational basis.
Josh Abbott, executive director of the center, said each two-year project features a workshop of leading experts in the first year, followed by a large, public conference in the second year. Previous projects have focused on topics such as concussions and Alzheimer’s disease.
The workshop on sex-based differences in the brain, which was not open to the public, took place Dec. 10 at ASU Law’s Beus Center for Law and Society in downtown Phoenix. The forum featured some of the nation’s foremost neuroscience scholars, such as Larry Cahill from the University of California, Irvine, who led the conversation; Northwestern’s Catherine Woolley; and ASU’s own Heather Bimonte-Nelson. They were joined by a diverse group that included neuropsychologists, psychiatrists, judges, professors and medical professionals from Mayo Clinic.
“We’re very excited about the mixture of the participants,” Grey said. “The workshop is designed for robust group discussion at a high level.”
‘An explosion of research’
Grey says MRIs, CT scans, PET scans and similar technology have served as game-changers in neuroscience research by allowing scientists to examine the structure and function of the brain.
“We didn’t have that capacity before,” she said. “With those developments in the last 15 to 20 years, there’s been an explosion of research in how brains operate and function, and how the nervous system operates.”
She said functional magnetic resonance imaging, which measures brain activity by detecting changes associated with blood flow, has been a tremendous breakthrough in revealing how the brain actually functions.
As researchers study and document sex-based differences in the brains and nervous systems of men and women, Grey says a primary goal is to help better diagnose and treat brain disorders — especially disorders that affect men and women differently in terms of incident rate or nature of the disease.
“So this is an outgrowth, some say, of the movement toward precision-based therapy,” Grey said. “That’s the way scientists view it, as a precision-based therapy, to help us better diagnose and treat brain disorders like PTSD or depression. And now it’s seen as a critical biological variable when they’re doing biomedical research.”
Examining the implications
But with the medical advances come a complex set of legal and ethical implications, some of which could alter the course of equality movements.
“For a long time, there was a lot of sex-based bias in the law, where men and women were treated differently based on assumptions that were not necessarily valid or fair, and I think there’s been a lot of historical injustice in the legal system that’s come out of that,” Abbott said. “The more recent approach has been to assume there are not differences unless there are compelling reasons to treat men and women differently in legal proceedings.”
But he says the sex-based brain differences now being identified between men and women may provide a basis for distinctions in how men and women are treated in certain legal settings.
Grey says the science could affect everything from criminal law and sentencing to forensic evidence, workplace discrimination and equality in education.
“Fundamentally, it could challenge our concept of equality in law, at least in certain areas,” she said. “So that’s why this is such a controversial and significant area of research. Do we want to have a universal legal standard of neutral application or recognize and embrace real differences?”
In terms of sexual discrimination in the workplace, Grey says research could document that men and women perceive threatening behavior differently, which could alter legal analysis of harassment.
“Some courts have actually accepted that we should define a hostile work environment from the point of view of a reasonable woman working in that job, as opposed to a reasonable person,” she said. “So if we could document that there are real differences, that could change how we analyze what harassment means in a workplace setting.”
Another specific area that could be challenged is the definition of severe emotional distress, which is tortious behavior if negligently inflicted on another.
“If, in fact, women generally perceive and respond differently to inflicted severe emotional stress than men do, we might need to reconsider what we think of as the harm in that setting,” she explained. “And it turns out that some of this research may lead to that conclusion that women and men on average have different responses to severe stress through their nervous system and through their brain system. Should the law take those differences into account?”
But as these differences are identified, some experts are cautioning against “neurosexism” — which, Grey says, means giving in to sex-based stereotypes, viewing differences as limitations or simply failing to recognize that some differences are cultural or social, rather than biological. As Grey says, when sex-based differences are identified in the brain, it is important not to assign value.
“A big goal in law is to always be objective and apply laws neutrally,” she said. “If women react differently than men, we don’t want to go backward and suggest that women are frail and they can’t take the stress that men can take. So we have to be very cautious as we start suggesting that women and men perceive and react to severely stressful situations differently.”