Science Finally Shows When (Cognitive) Adulthood Begins

No, this is NOT the usual "teen brain" junk science that we have quite frankly gotten tired of debunking.  This is the real deal, so listen up and pay very close attention. 

Researchers at the University of Pittsburgh recently published a new, large, and groundbreaking study in Nature Communications that examined nearly two dozen laboratory measures of "executive function" of a whopping 10,000 participants (ages 8 through 35) across four different datasets.  And the results dovetail nicely with what we at Twenty-One Debunked have been generally saying all along, and we quote (emphasis added):

"The resulting analysis showed a common dynamic of executive function maturation that was shared between both sexes: a rapid burst of executive function development in late childhood to mid-adolescence (10-15 years old), followed by small but significant changes through mid-adolescence (15-18) that stabilized to adult-level performance by late adolescence (18-20)."

"Other important behavioral factors that complement executive function, such as the ability to control one's own emotions, can change with age. The ability to use executive function reliably improves with age and, at least in a laboratory setting, matures by 18 years of age."

In other words, 18-20 year olds are in fact adults, not only biologically, but also neurologically and cognitively as well.  And the data show that even 15-17 year olds are actually pretty darn close as well.  Thus, there is really no scientific reason to set the age of majority (or any related age limit for that matter) any higher than 18, period.  In fact, one can even justify setting some age limits a bit lower than that based on this research (after all, it's not binary like flicking a light switch, but rather a gradual process).

So why have so many other, flashier studies seemed to have suggested otherwise?  Well, the brain technically does continue developing to some extent well beyond 18, of course, but that apparent development has been known for over a decade now to continue well into the 30s, 40s, and likely even beyond that as well.  Clearly, any development that does occur from 18 to 21 or 25 is on the very same spectrum as the development that continues beyond that as well.  A brain that continues to change and develop throughout life does not lend itself to simplistic explanations of a magical age of neurological adulthood based on its superficial appearance on a brain scan.  Rather, the real question becomes when the brain is no longer developing on a critical or fundamental level, and when one can achieve an adult level cognitive capacity and performance.  And the University of Pittsburgh study above answers that question far better than just about any other study has so far to date.

So basically, we as a society have three choices on what to do given these findings:  1) radically redefine adulthood, 2) radically redefine adolescence, or 3) simply accept 18-20 year olds as adults, in every way, period.  Occam's Razor would clearly agree with the third option, as would any serious consideration of liberty and justice for all.

To argue otherwise is, at this point, nothing short of warmed-over phrenology at best, if not full-blown political Lysenkoism that will ultimately go down in history as the epitome of bigoted crank science.

UPDATE:  Much to the chagrin of some purists, this study is also the strongest hard evidence to date that adolescence does in fact exist as a distinct life stage that is not entirely socially constructed.  Adolescence appears to be no more socially constructed than adulthood is, in fact.  And to that we say, so what?  Glibly denying all group differences and/or attempting to erase adolescence entirely does not do young people any favors either, and it plays right into the hands of the biological determinist bigots and cranks.  That said, the study finds no scientific support for the specious idea of "emerging adulthood" as a life stage somehow distinct from young adulthood, and we really should simply jettison the term "emerging adulthood" from our collective vocabulary. 

In any case, there is nothing magical about turning 21, 25, or any other age north of 18 for that matter.  And while even 18 is hardly magical either, it is arguably the least arbitrary place to draw the default line where once you are an adult, you are an adult, period.