Recently, the journal Biological Psychology published an article about brain responses to violence in youths with aggressive conduct disorder (CD). On Nov. 12, it was the topic of a blog entry on the New York Times's website and on Nov. 18, Slate attacked both the blog and the original study. I read these three items in the opposite order that I should have. The reasonable thing to do would have been to start with the journal article to form my own impressions, then read the Times blog, and finally read the Slate article.
However, I came across the Slate article, written by Daniel Engber, first and found it convincing until I read the original article. I agree with Engber's first two main points. The participants in the study, who exhibited signs of aggression including "starting fights; bullying using a weapon; theft with confrontation of the victim; physical cruelty to people; cruelty to animals and forced sex" should not simply be called bullies. (Although Engber shows a bit of bad science on his part in suggesting that these youths with CD should be called sociopaths- the Biol. Psych. article points out that CD is a precursor to Antisocial Personality Disorder, not a synonym for it). His second point is "the 'aggressive youths' never inflicted any pain (real or imagined) on other people during the experiment. Whatever enjoyment or dismay they felt came from viewing a set of photographs depicting, for example, someone stepping on somebody else's toe. So the brain-imaging data may tell us what it's like to watch a bully but not necessarily what it's like to be a bully."
To be fair, I also agree with his third argument "the brain scans themselves are open to interpretation," but unlike him, I don't think this is a downside of the study. Of course brain scans are open to interpretation. All science is and should be open to interpretation. This doesn't make the study "iffy" or "questionable" as Engber describes it. The researchers also aren't shy about this fact. Among other admissions, they write, "There are important reasons to be cautious when interpreting the activation of the striatum as indicating a positive affect response to viewing others in pain, however...In humans, the striatum is activated by stimuli associated with reward, but also by salient aversive, novel, and intense stimuli."
Engber writes, "Let's pretend there were some good reason to wonder how much fulfillment a bully finds in his daily wedgies. The University of Chicago research wouldn't help, even if we cared to know." The reason why it might not help is because that wasn't the point of the study. The goal was to determine if youths with CD "exhibit atypical empathic responses to viewing others in pain." The findings were complicated, and in some cases, conflicted with previous studies. For instance, the researchers found no reduced amygdala responses in subjects with CD, in contrast to previous studies.
So why does this subpar journalism matter? It's because one day (if it hasn't happened already) some lawyer will show jurors a brain scan and try to convince them that it proves the defendant either enjoys or doesn't enjoy others' pain. Normally, I would think that a juror who had read about a neuroscience study like this one in Slate or the Times would be well-informed about it and able to make a reasonable decision. Unfortunately, that's not true in this case.