By Duncan Richter
I was part of a discussion at my school this week on poverty and psychology. It was a good discussion, but one thing that struck me about it was the way that changes to the brain are regarded. I'm speaking about a vague sense here, somewhat similar (although opposite) to the vague sense I have about the way Islam is regarded. Just a few years ago my students seemed to regard Islam as just another religion, one that most of them happened not to believe in. These days it seems to be viewed as something positively evil. This is a vague sense, as I say, but it shows up in concrete ways, such as students being noticeably reluctant to say Muslim prayers if a fellow student is trying to get them to join in during a presentation. Changes in the brain seem, in a similarly vague yet detectable way, to be viewed as important in a way that non-physical changes are not.
Here's an example, from a New York Times story called "How Walking in Nature Changes the Brain." It's about a widely reported study about the effects of walking in greenery compared with the effects of walking along a highway. Consider this part of the story:
As might have been expected, walking along the highway had not soothed people’s minds. Blood flow to their subgenual prefrontal cortex was still high and their broodiness scores were unchanged.
But the volunteers who had strolled along the quiet, tree-lined paths showed slight but meaningful improvements in their mental health, according to their scores on the questionnaire. They were not dwelling on the negative aspects of their lives as much as they had been before the walk.
They also had less blood flow to the subgenual prefrontal cortex. That portion of their brains were quieter.
These results “strongly suggest that getting out into natural environments” could be an easy and almost immediate way to improve moods for city dwellers, Mr. Bratman said.
The "strongly suggested" results are precisely the results that "might have been expected." Why is this news? Leaving aside the reasons to have doubts about the science involved, it seems to me that it's the brain-stuff that makes it seem newsworthy. If people simply reported feeling better or worse after walks in different environments no one, I suspect, would care. It's the claim that there are detectable changes in the brain that gets people's attention.
Googling "actually changes the brain" brings up lots of articles. Meditation, PTSD, reading to kids, marijuana, counseling, and learning all supposedly change the brain. It sounds exciting, but almost everything changes the brain. What matters is whether the changes are significant and long-lasting. I don't think the nature walks study even claimed to look at that. In other words, a lot of people appear to get excited by evidence that just a very little thought reveals to be insignificant.
Surely this is the kind of thing, or one of the kinds of things, that prompts calls for more and better critical thinking. It isn't a particularly philosophical virtue. In fact I recently taught a class on poverty in which I showed a graph depicting the correlation between economic inequality and various social ills, and it was the psychology majors who were asking about standard deviation and so on. What matters in these cases is knowing something about statistics, knowing something about the brain, and knowing when you don't know, so that you don't mistakenly think you understand psychology or economics or whatever just because you have read a few newspaper articles about it. Philosophy can be especially helpful here, I think, because a characteristic of philosophy is asking 'Why?' and looking for reasons for belief. Other disciplines do this too, of course, but less universally. In most sciences you reach a point where you stop asking why (this is not a criticism, just a feature of disciplines with specific boundaries), but in philosophy you really are not supposed to stop. (And in less rigorous disciplines there might be very little asking why in the first place. ) Perhaps the ideal critical thinking course would cover everything you need, but I think part of what you need in order to be recognized as a critical thinker is rigorous training in some discipline so that you know what careful study is and know that you are no expert, and therefore not qualified to opine on, areas you have not studied. No single course can teach that lesson.
But I didn't mean to get side-tracked into a discussion of critical thinking. I'm at least equally interested in the phenomenon of what Anscombe calls words' acquiring "mere mesmeric force." The word "brain" and the words "changes the brain" seem to have acquired some of this force. It's an interesting phenomenon. (And part of critical thinking, I would think, is to be aware of this phenomenon and try to resist it.) It's not that the word 'brain' is meaningless in the way that Anscombe thinks the specifically moral use of 'ought' is. But it is a word that should probably often set off bullshit-detectors. And maybe "actually changes the brain" is meaningless except in cases where the change is major and long-lasting.