CAN WE PLEASE SETTLE ON A LEGAL AGE OF MAJORITY?

A Boston Globe opinion piece by a psychology professor named Laurence Steinberg predicts that Dzhokhar Tsarnaev's lawyers will argue that he was only kinda-sorta over the adult age threshold at the time of the Boston Marathon bombings, as a way of trying to save him from the death penalty. Will this really happen? And is this an odd line of argument when our legal system treats much younger defendants as full-blown adults?

As the trial of Dzhokhar Tsarnaev, the accused Boston Marathon bomber, moves into its defense phase, his attorneys likely will lean heavily on the science of adolescent development to argue that their client should be spared the death penalty. Judy Clarke, Tsarnaev’s lead defense attorney, has already made several references about Tsarnaev’s youthfulness and susceptibility to the influence of his older brother....

Tsarnaev was 19 at the time of the bombing, an adult under every state’s criminal law. States often have departed from the presumptive age of majority, 18, in prosecuting and punishing juvenile offenders, but the departures always have been toward a younger, not older, dividing line. Arguing that a 19-year-old is still an adolescent is a step in a new direction.

I'll say. In Wisconsin last year, two twelve-year-old girls were charged with stabbing a classmate in an effort to appease an Internet-based fiction character called Slender Man; earlier this month, a judge ruled that the two girls should be tried as adults. Obviously, the defense in that case will raise the subject of the girls' age -- appropriately. But why are we even arguing that two girls of this age are pseudo-adults before the law?

The two defendants in that case are white, but it's primarily nonwhite youths who get tried as adults in America. A quick Google search finds these headlines: "Black Missouri teens increasingly tried disproportionately as adults"; "Black, Latino youths disproportionately sentenced in adult courts" (in California); "Black boys are more likely to be tried as adults in Chicago"; "Colorado minority youth disproportionately tried as adults."

In his article, Steinberg points out that the Supreme Court has embraced the notion that adolescents aren't fully capable of adult decision-making, although the Court has primarily focused on minors:

The defense team will probably point to several US Supreme Court decisions issued during the past decade, in which the Court’s majority concluded that adolescents’ immaturity rendered them less culpable than fully mature adults. Writing for the court’s majority in Roper v. Simmons, the case that abolished the juvenile death penalty, Justice Anthony Kennedy identified three features of adolescence that mitigate juveniles’ culpability: impetuous decision-making, heightened susceptibility to coercion, and an unformed personality.

In subsequent decisions that built on Roper, the court connected adolescent impulsivity to research on brain development, arguing that adolescents’ neurobiological immaturity meant that their crimes are often due to factors they can’t control. More recently, research also has identified the neural bases of adolescents’ intensified susceptibility to peer pressure and is revealing the period to be one of heightened neuroplasticity, or capacity for the brain to change.

But how often do we apply this in the cases of nonwhite youths charged with run-of-the-mill crimes? Do we say that a nineteen-year-old charged with a gang-related shooting -- or, for that matter, a nonwhite sixteen-year-old being tried as an adult -- ought to earn our empathy because his adolescent brain hasn't developed full maturity? Is that happening in our courts on a routine basis?

I think what Steinberg is talking about is scientifically valid. But I also think we need to decide who's an adult in this society and who isn't for the purposes of the law -- and we ought to try to apply a single standard. If we're going to let some lawyers argue that a nineteen-year-old bomber was a still-developing child, we shouldn't be saying that two twelve-year-old girls are adults, or that thousands of nonwhite teenage boys caught up in the criminal justice system are also adults well before their eighteenth birthdays. It makes no sense.