Neuroscience helped debunk the superpredator myth—and sway the Supreme Court. Why the movement to overhaul juvenile sentencing is picking up steam.

Princeton political scientist John Dilulio dubbed them superpredators—murderous teenagers who could commit heinous acts of violence without feeling a trace of guilt. “They fear neither the stigma of arrest nor the pain of imprisonment,” Dilulio wrote in 1995. “They live by the meanest code of the meanest streets.” According to Dilulio, the country was on track toward a scourge of youth superpredator violence, precipitated by troubling demographic shifts (read: more black kids) and a perceived morality deficit. The crisis, it seemed, was inevitable. Harrowing true-crime headlines splashed across the covers of Time and Newsweek. State and federal lawmakers scrambled to toughen sentencing laws for juvenile offenders. And Americans everywhere braced for the insurgence of some 30,000 new teen superpredators that Dilulio predicted would roam the streets by the end of the decade.

But for all the fear and frenzy, America’s teen violence apocalypse never arrived. In fact, the exact opposite happened. Juvenile violent crime rates that were forecast to double instead dropped by more than 50 percent, and advances in modern neuroscience began to complicate the prevailing superpredator caricature. Soon even Dilulio was walking back his claims. “Thank God we were wrong,” he told the New York Times in 2001. “I’m sorry for any unintended consequences.”

Yet those unintended consequences now litter the country’s federal and state justice systems. Today, kids as young as 11 years old are still being tried as adults, and many mandatory-minimum sentencing laws passed in the 1980s and '90s remain on the books—even in progressive states like Oregon.

The mythical superpredator continues to cast a long shadow over American politics, but a promising reform movement—helped along by the Supreme Court—has recently made some major strides: In 2005, Roper v. Simmons banned the death penalty for juvenile offenders; in 2010, Graham v. Florida prohibited juvenile life without parole (JLWOP) sentences for non-homicide offenses; and in 2012, Miller v. Alabama nixed state laws requiring mandatory life without parole for juveniles, regardless of the crime. Here are five studies that explain why the movement to overhaul juvenile sentencing laws has been picking up steam—and what could still slow it down.

THE PARTS OF THE BRAIN RESPONSIBLE FOR IMPULSE CONTROL ARE UNDERDEVELOPED IN ADOLESCENTS

Parents didn’t need fMRI scans or controlled behavioral analyses to know that their teenage children take more risks, seek more thrills, and make more impulsive decisions than they do (presumably moms and dads reached those conclusions somewhere in early antiquity). What modern science has helped explain is why. Beginning in the 1990s, a series of landmark studies found that the brain’s frontal lobes, where many decision-making processes occur, continue to develop throughout adolescence. Researchers also learned that the brain’s reward-seeking impulses develop faster than its cognitive control systems—an imbalance often compared to firing up a high-speed race car before fully installing the brakes.

Amid these advances in neuroscience, Temple University psychologist Laurence Steinberg helped untangle the implications for juvenile justice. In a 2009 paper, he outlined the mounting evidence that, especially when faced with peer pressure, teenagers are more likely to take risks and engage in sensation-seeking behaviors, including crime. Steinberg concluded that, because restricted brain function is at least partially to blame for juvenile delinquency, teenage offenders should be held less criminally responsible than adults—an argument that has held sway with the Supreme Court.

—“Adolescent Development and Juvenile Justice,” Laurence Steinberg, Annual Review of Clinical Psychology, Vol. 5, April, 2009.

BUT NOT EVERYONE AGREES ON WHAT BRAIN DEVELOPMENT MEANS FOR DETERMINING CULPABILITY

“Brains do not commit crimes; people commit crimes.” That’s the opening salvo of Stephen F. Morse’s assault against “Brain Overclaim Syndrome”—his phrase for researchers’ over-eagerness to insert neuroscience into the assessment of criminal responsibility.

In his essay, Morse hints at a sobering thought experiment: Imagine if scientists discovered that delinquency was influenced not only by adolescent brain development, but also by the position of the moon and the stars in the night’s sky. Should those astrological factors reduce a criminal’s culpability? Ridiculous, right? But Morse and other “neuroskeptics” argue that pegging criminal culpability to neuroscience relies on equally flawed logic. Brain function might offer an explanation for criminal behavior, they say. But in a court of law, it shouldn’t offer an excuse.

—“Brain Overclaim Syndrome and Criminal Responsibility: A Diagnostic Note,” Stephen F. Morse, Ohio State Journal of Criminal Law, Vol. 3, 2006.

JUSTICE SCALIA WANTS CULPABILITY TO BE CONSISTENT—BUT RESEARCHERS SAY CULPABILITY WILL ALWAYS BE CONDITIONAL

In his Roper v. Simmons dissent, Justice Antonin Scalia took a swipe at the American Psychological Association for supporting the juvenile death penalty ban. His beef: If juveniles are responsible enough to make their own abortion decisions (as the APA argued in Hodgson v. Minnesota), mustn’t they also be responsible enough to be held accountable for murder?

Studies by researchers at the Sackler Institute for Developmental Psychology suggest it’s not that simple. In the presence of certain emotional cues (think peer pressure), adolescents demonstrated less impulse control than both children and adults. But subtract those emotional cues and teens performed no differently. Echoing Steinberg, the authors argue that, when teens must make snap judgments in emotionally charged environments, they’re indeed more likely to act impulsively and take irrational risks. But in cooler scenarios—like, say, when choosing whether or not to have an abortion—juveniles can match the decision-making capacity of adults.

—“The Teenage Brain: Self-Control,” B.J. Casey and Kristina Caudle, Current Directions in Cognitive Science, Vol. 22, No. 2, 2013.

ONCE CONSIDERED FUTILE, THERAPY IN PRISON IS REDUCING THE RECIDIVISM RATE FOR RELEASED JUVENILES

In 1974, Robert Martinson and his colleagues summarized the effectiveness of prison rehabilitation efforts in stark terms. Basically, they said, nothing works. The Martinson Report would become popular gospel in the United States, influencing the tough-on-crime doctrine that ushered in harsh prison sentences for criminal offenders, including juveniles.

But now the report’s dreary conclusions are being called into question. A 2005 study points to the particular effectiveness of multisystemic therapy, an approach that emphasizes involving family members in the rehabilitation process. The study, which focused on violent juvenile offenders, found that inmates who participated in multisystemic therapy experienced a long-term recidivism rate of 50 percent—down from 81 percent among inmates who only received individual therapy. Members of the multisystemic therapy group also experienced 54 percent fewer arrests than the control group.

—“Long-Term Follow-Up to a Randomized Clinical Trial of Multisystemic Therapy With Serious and Violent Juvenile Offenders,” Cindy M. Schaeffer and Charles M. Bourduin, Journal of Consulting and Clinical Psychology, Vol. 73, No. 3, 2005.

WE'RE ON THE RIGHT PATH—BUT NOW SCOTUS MIGHT HAVE TO LEAD PUBLIC OPINION

When SCOTUS issued its Roper v. Simmons decision in 2005, the Court had public opinion firmly on its side. According to a 2002 Gallup poll, only 26 percent of Americans believed juvenile offenders should be eligible for the death penalty—well shy of the 72 percent who supported the death penalty for adults. But if SCOTUS decides to expand the scope of Miller v. Alabama by imposing a complete prohibition on JLWOP sentences, public opinion would likely be less favorable.

Although no Gallup poll has measured national support for JLWOP, a study in Colorado found that 53 percent of respondents supported life without parole for juveniles who had murdered a stranger. The authors speculate that an entrenched fear of teen superpredators may still be shaping public opinion on juvenile justice policy—even two decades later. But if history is a guide, the Court itself can help separate public paranoia from rational policy.

—“Attitudes Regarding Life Sentences for Juvenile Offenders,” Edie Greene and Andrew J. Evelo, Law and Human Behavior, Vol. 37, No. 4, 2013.

Five Studies is Pacific Standard’s biweekly column that identifies and analyzes the best academic research to deliver new insights on human behavior.