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Politics aside, the sexual assault allegation against Supreme Court nominee Brett Kavanaugh has raised questions — and misconceptions — about adolescent development, the teenage brain and how we remember traumatic events.
One: “Boys will be boys,” or the idea that teenagers can’t help but follow their impulses. In USA Today, education professor Jonathan Zimmerman wrote that “Of course [Kavanaugh] was different then; he was a third of the age he is now. And teens do stupid, dangerous and destructive things.” Law journalist Emily Bazelon of New York Times Magazine said that “we know the adolescent brain is still developing, and teenagers on average aren’t super good at impulse control.”
Another centers around what Christine Blasey Ford, who accused Kavanaugh of sexually assaulting her while the two were teenagers, remembered. Fox News’ Tucker Carlson said Tuesday that “Human memory is notoriously unreliable, especially over time” and Vox’s Alvin Chang echoed “To be clear, Carlson’s point isn’t entirely off-base. Research shows that our memory is pretty bad, which is why most of us probably don’t remember a drunken night last month, much less 36 years ago.”
These characterizations oversimplify how the teenage brain and memories work, particularly when it comes to sexual trauma, according to four neuroscientists and three criminologists who spoke with the PBS NewsHour.
While it is tempting to write off sexual aggression as an unfortunate consequence of adolescent impulsivity, in reality, risky behaviors like sexual assault involve brain capabilities that are established before and after our teenage years. Moreover, the company we keep plays as big a role in sexual assault as impulses. And traumatic memories tend to last for the survivors, no matter the age they are when an incident occurs.
Here’s what science tells us know about teenagers, sexual assault and remembering trauma.
Around 750,000 people were raped and sexually assaulted in 2015 and 2016, but only 37 percent of these cases were reported to the police, according to the National Crime Victimization Survey. This limits our understanding of who commits sexual assault and why.
“Unlike other types of criminal offenders, those who commit sexual offenses can be very varied,” said Elizabeth Jeglic, a clinical psychologist at John Jay College of Criminal Justice. “We see people in the Catholic Church. We see doctors, we see lawyers but we also see people who have less education. It’s across the board, across socioeconomic status, across race and ethnicity.”
General patterns do emerge:
Data also shows sexual assault disproportionately affects youth.
“Younger persons are more likely to be both offenders and victims of crime, including rape and sexual assault,” said Janet L. Lauritsen, a criminology and criminal justice professor at University of Missouri – St. Louis. “Adolescents — ages 12 to 17 — have slightly higher [sexual victimization] rates than 18 to 34 year old. The risks are about eight to nine times greater for women under age 34 than for women ages 50 and above.”
These sexual offenses begin to spike right as men head to college. Once puberty begins around the age of 10, the rate of arrests for rape begins to steadily rise.
On average, 18.5 per 100,000 males aged 10 to 17 are arrested for rape, according to data provided to the PBS NewsHour by the Bureau of Justice Statistics. For college-aged men, this figure nearly doubles to 32.9 per 100,000, but arrests drop off as males reach their mid- to late-20s.
These trends in sexual offenses parallel key stages in mental development.
Self-control, regardless of age, involves a balance between rational decision-making and our desires for rewards like sex, food and emotional fulfillment.
These exist in two separate parts of the brain.
The primal part of the brain that handles emotions, impulses and aggression resides toward the back of our heads, near our ears. Our decision-making centers — for controlling impulses, planning and organization and judging consequences — live right behind the forehead in the frontal lobes, namely, the prefrontal cortex.
How we balance the two depends on how our brains build their wiring. This happens as soon as we’re born and lasts through about age 30. When we’re born, our brains are messy. We have more neurons (nerve cells) than we need to survive and an overabundance of communication lines between those cells.
During childhood and adolescence, our minds constantly rewire — pruning and rebuilding connections — through a process called synaptic plasticity.
“All the building blocks for synaptic plasticity are set at higher levels in the childhood and adolescent brain than they will be in adults,” said Frances Jensen, chair of neurology department at the University of Pennsylvania and co-author of The Teenage Brain: A Neuroscientist’s Survival Guide to Raising Adolescents and Young Adults. “That’s why adolescents and children can learn things much more rapidly than adults.”
Our primal areas become fully wired before the ones made for rational thinking. That’s because some of the messages sent between neurons must travel long distances across paths coated in a fatty substance called myelin.
This process starts in the back of the brain, with the emotions; myelin development here wraps up by early adolescence.
Frontal lobes lag behind, which means the paths that carry decision-making skills don’t catch up until your late 20s. Some studies show the parts of the brain controlling emotionality, sexuality and risk-reward are turned on twice as much in teenagers compared to adults exposed to the same experience, Jensen said.
As a result, teenagers can be quick to react emotionally and to seek instant gratification — because those parts of their brains are operating at a faster speed.
“This is why adolescents can become addicted to all manner of things — opioids, cannabis videogames,” Jensen said. “Addiction is just another form of plasticity, except with your reward circuit. They are more rapidly hardwiring themselves.”
This tendency to overvalue rewards and emotions continues until the frontal lobes catch up, plug into the primal brain and suppress these reactions. Girls grow out of these habits about two years, on average, before boys.
Overall, that’s why teenagers often get cast as unruly louts, whose actions are ruled by their impulsive choices. But that’s not the whole story.
“People often talk about adolescence as if we do not have the cognitive ability to decide what is right and wrong or to control our behaviors. This is not true. It’s too simplistic,” said Tomas Paus, director of the population neuroscience and developmental neuroimaging program at the Bloorview Research Institute in Toronto. “By the age of 12 or 13, our brains are pretty mature. There is no hardcore evidence that young people completely lack impulse control.”
“What we find with college students is that those who are most likely to sexually assault women have friends who encourage that and friends who do it,” DeKeseredy said. “If men in these groups feel that they’re not getting as much sex as their friends, then they’re more likely to engage in sexual aggression so that they could live up to their peers’ expectations.”
This concept becomes apparent when you consider how teenagers behave under peer pressure. Our brains are continually shaped — from childhood to adulthood — by our social enclave, Paus said.
Behavioral experiments show if a teenager is sitting alone in a room, they’re much less likely to take risks than if they are in the presence of their peers.
“There’s something about being around your peers during adolescence that changes the way your brain works,” said Laurence Steinberg, a psychologist at Temple University who led the work behind this discovery. Using brain scans, his team found the sway of peer pressure fades as people age into adulthood.
This pattern means the adolescent brain can decide between right and wrong. They can choose to suppress their impulses in the right context, Paus said. Teenage girls go through the same evolution of their primal brains, emotions and impulses as boys — but are far less likely to commit sexual assault.
DeKeseredy argued that sexual assault has more ties to power and control than impulsivity. Psychological tests show individuals with histories of rape tend to struggle with impulse control, but not everybody who commits rape has an impulse control problem.
Jeglic and Steinberg agreed, citing that a large number of rapes are premeditated. About 90 percent of sexually assaults involve people who already knew each other.
Our memories guide how we behave in the future. When we encounter a welcoming person or place, we build memories to lead us back there. In contrast, if something hurts us — like the first time we burn our hands on a stove — we remember to avoid it.
Traumatic experiences take normal memory formation to another level.
“Any experience that threatens our survival is remembered and recorded very fast,” said Jacek Debiec, a psychiatrist and neuroscientist at the University of Michigan who studies traumatic memories and how their stored in the brain.
Traumatic memories last our whole lives and are resistant to change. Photo by Photographee.eu/via Adobe Stock
Humans typically need repetition to learn and remember. But traumatic memories can form after a single, life-threatening event because, from an evolutionary perspective, your brain may have only one chance to capture it.
For this reason, traumatic memories last our whole lives and are vivid — filled with details like sounds, scents and sights. Traumatic memories are reinforced by our brain’s fear center — the amygdala — as well as by stress hormones like cortisol.
But memories aren’t static — in the short-term or in the long-term.
In the immediate hours after we make a memory, it is unstable and vulnerable to editing. Once this window of opportunity passes, our memories become more lasting and persistent.
Recalling an event after days, months or years can also open the door to memory editing due to phenomena called reactivation and reconsolidation. Tucker Carlson and Alvin Chang hint at these processes in their commentaries — but leave out a crucial exception:
Recalling a traumatic memory typically strengthens it.
“In our experiments, when the traumatic memories are activated, there is an associated arousal and higher levels of norepinephrine, which mediates arousal,” Debiec said. “Then these traumatic memories are strengthened.”
When editing does occur, it tends to only influence peripheral details — like what an attacker was wearing. Central aspects surrounding an event, namely ones with emotional significance — like the people involved and the mode attack — stay consistent.
What happens to memory formation when a person is drunk?
Blasey Ford said she had one beer the night of incident but alleges that Kavanaugh and Judge were heavily intoxicated. (Kavanaugh has “categorically and unequivocally” denied the allegation of sexual assault altogether). Large amounts of alcohol can block memory formation, Debiec said, but if a person is able to remember details that accompany the event, then it’s likely the alcohol didn’t distort the original memory
“The traumatic memories are biologically privileged,” Debiec said. “Unlearning trauma takes much more time and effort, and it probably never could be fully complete.”
Nsikan Akpan is the digital science producer for PBS NewsHour and co-creator of the award-winning, NewsHour digital series ScienceScope.
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