First, despite the cautionary stance of the abstract, the introduction ends with this telling statement:

Finally, in the fifth section, I argue that the Roper court made the correct decision on this issue and suggest that several issues still need to be resolved before brain imaging can even be considered for use in the criminal justice context.

Yet the whole point of this article according to the abstract is "first and foremost, no definitive link between brain structure and deviant behavior has been established" (emphasis added). If that is the case, and this article is not examining moral or ethical reasons for abolishing the death penalty for juveniles, then how on earth can such a conclusion be logically reached? If the science is so new and so limited that no definitive links exist between the behavior in question and the scientific findings then why should the science be cited as authority for the fashionable claim that adolescents substantially lack the biological maturity of adults, and thus, should be categorically excluded from the death penalty?

Second, let's look at this quote "reviewing" the purposes of punishment in criminal law:

Before delving into the details of Roper (2005), it is first necessary to review some basic tenets of the Anglo-American criminal justice system. Most important, punishment for a violent criminal act is meant to serve two functions: retribution and deterrence. It is assumed that punishment will somehow compensate the victims and society for the crime and will prevent the offender, along with other potential criminals, from committing a similar act in the future.

Is that so? Perhaps many folks do believe that the sole function of retribution is a sort of compensation for the wrongful behavior but another reasonable explanation is that society can justly require convicts to suffer the measure of punishment for its own sake. A sort of collective catharsis. Since when is it mandatory that some sort of measurable "compensation" be required before a penalty is imposed? It may be a good public policy that our criminal punishments "produce" results: lower recidivism, deterrence, etc., but our legal traditions surely do not require it.

Putting that aside, let's move onto the nuts and bolts of this article which is essentially a review of brain imaging findings regarding juveniles and brain development. And here's where the article really suffers. It begins:

The diagnosis of frontal lobe pathologies has been revolutionized by advances in brain imaging technologies such as computerized axial tomography (CAT or CT scan), positron emission tomography (PET), and MRI.

This is the typical rhetoric of many (but not all) of the brain imaging folks these days. But I'd like to know of just one diagnosis of frontal lobe damage outside of traumatic brain injury or cancer in which brain scanning has "revolutionized" diagnosis. The closest we can get to is schizophrenia, which indeed, involves the frontal lobes and brain imaging has given us a better understanding (but not diagnosis of). But: (1) Schizophrenia is a global brain disease that involves a lot more than just the frontal lobes, thus we can be much more confident in the findings because the brain scanning findings comport with histopathlogical findings at autopsy. (2) By far the greatest advances in understanding scizophrenia in terms of brain imaging have involved global gray matter loss over time which is: (a) a structural finding, not functional (fMRI, which measures glucose metabolism in the brain is what all of the sexy brain imaging stuff is centered on these days. Let's just put aside the fact that there's a delay between activation of the neuron and the supposed measurement of the activity by the scans using the common technique, BOLD, all of which is estimated by the computer software used in brain scans. And let's also put aside the imaging smoothing techniques which impute missing data and which a senior statistician at the National Institute of Health told me hardly anyone understands) (b) schizophrenia involves a disease that has been long recognized in our law as associated with severe impairment of the mind, and hence, deserving of mitigation defenses. Even Blackstone referred to punishing "madmen" as morally wrong. But adolescence is a a relatively new phenomenon in our world and what the juvenile death penalty opponents were purposing is categorically excluding an entire group who appear cognitively competent on the surface, but were argued to be substantially immature and incompetent to understand the ramifications of the penalty based on the findings of a few brain imaging studies.

Oh, and what about those brain scanning studies of adolescents? Almost all of them, as Aronson uncritically accepts as demonstrably true, involve samples of less than 20 persons. Power analysis anyone? These are extremely small samples in which statistical comparisons between two groups borders on statistical sophistry. Sure, brain scanning is expensive and thus small samples are almost always the norm, but that does not change the fact that statistical comparisons between groups generally requires samples greater than 20 individuals.

Another aspect that is completely ignored by many brain scanning experts (but which they surely know of) is brain plasticity. It is known that the when one area of the brain is damaged, underdeveloped, or somehow impaired, other areas of the brain often take over the functions of the damaged/underdeveloped area. It is entirely possible that the areas considered underdeveloped and of importance for juveniles and culpability are under the control of other areas of the brain. From everything we've learned in the past 20 years in neuroscience (and we've learned a lot) we have more questions than answers. There's simply so much we don't understand. Concluding that all adolescents have brains ill-equipped at moral responsibility flies in the face of hundreds of years of common sense that surely we need more than a handful of questionable brain scans to overturn.

Or do we? As Aronson discusses, in Roper v. Simmons, the Court further develops its "evolving standards of decency" doctrine which, apparently, is left to nine unelected judges to determine for the rest of us. Of course the Court engages in an entirely disingenuous analysis of this new doctrine by claiming that this new standard flowed from a "national consensus" that executing juveniles is morally wrong (never mind that the court was suppose to decide whether the penalty was Constitutionally defective; not morally wrong). But as Justice Scalia aptly notes in his dissent, a commonsense definition of "majority" of U.S. states should equal at least 26, not 12.

But Aronson just accepts that the neuroscientists and the Court are correct despite "my own intuition is that social and economic factors are more important determinants of adolescent crime than biological ones and that notions of culpability ought to be based on socially determined ideals of justice rather than on science."

But we should not be surprised about this captious reasoning, since the journal that published this article is indisputably biased when it comes to the death penalty. There have been at least 2 entire issues within the past 10 years or so devoted to the death penalty in Psychology, Public Policy and the Law and not one article supporting an opposing view. As Justice Scalia noted in Kansas v. Marsh, one study published there, often touted by death penalty opponents, was so erroneous and weak it's remarkable that it was published at all.

There are indeed good moral arguments for the abolition of the death penalty for juveniles. But that's not what Roper was based upon. Instead, the Court, like many journal articles on the topic, engaged in uncritical, cherry-picking exercise of questionable and/or limited scientific evidence that we should all be wary. It is precisely because journals like Psychology and Public Policy and the Law give the appearance of scientific certitude when in actuality they are engaged in a thinly-veiled attempt at politics that we all need a healthy dose of skepticism when novel science claims are made in support of normative arguments.