I am a big fan of science. Studies, statistics, innovations in technology, you name it. Probably because I grew up in a family interested in debate and discussion and opinions only get you so far in those instances. In recent years, my mother in particular has embraced her Inner Skeptic and has encouraged me to do the same.
And, really, I think it’s high time for me to share the love of the Inner Skeptic with the world. Yes, that’s right. I am sharing the love. Sharing it. With you. So you’d better read on to see how this love will be shared.
I. Embracing Your Inner Skeptic
I’ve been embracing my Inner Skeptic for quite some time. I have peppered some of my posts with skepticism, and even have the small category specifically devoted to skepticism. But I’ve never really written one (or more) posts devoted specifically to looking critically at science. Not through lack of want, but rather because I didn’t have anything to push me into writing on the subject.
That is until one man, Scipio, decided to write about how “evil” women in comics are unrealistic because women aren’t as aggressive as men. He then backed his assertion of this innate state of women with a 2002 study on the neurobiology of aggression conducted at the University of Pennsylvania (UPenn). I read the article (which doesn’t even link to the original study [PDF]!), which in no way was a blanket endorsement of Scipio’s views, and decided it was high time for me to write an article on embracing your Inner Skeptic.
I know that all of us — myself included — can get super excited over the latest study and go overboard in supporting it without looking at important things like sample size and if it has been reproduced yet or not. This is, I think, part of human nature. But it’s important not to get so caught up in thinking of science as “facts” that we forget that most of the time the “facts” are our interpretation of the evidence, especially when the information on the studies comes only from news articles.
I’m saving the lecture on why not to confuse an article with a study for its own post, but here I will be discussing how to ask the “right” questions and why it’s valuable to understand the layers of interpretaiton, and how that differs from the empirical data. The point is not to discuss the relative merit of Scipio’s, or even the UPenn study’s, points, but rather to use this discussion as a springboard in order to excersise those critical thinking muscles that we all have.
II. Asking the Right Questions
One study does not evidence make. One study is merely a beginning. The UPenn study, for instance, is far from a definitive blow for innate differences. The title of the article itself even uses the word “possible” in it. Later on, it emphasizes that this was the “first time” such a thing has been measured. It even goes on to state that “[t]he findings provide a new research path” — meaning that more research needs to be done before anything else.
But the age of the study and if it has been reproduced yet are only two of the questions that should be asked. Sample size is another. The age, races, social background, ethnic background, and gender and sex of the participants is important too.
On the Evil Woman! post, Ragnell asks these questions as well as ones specific to the type of the study and the way that Scipio uses it to “prove” his point:
Are there other parts of the brain that can compensate for this particular part?
Is this a section of the brain determined by biological hardwiring alone, or can it be influenced to develop differently at an early age?
If it is the second answer, can the early social conditioning given to a little girl have nutured this area of the brain? What about the social conditioning given to boys? Is it possible that our cultural mores are causing early harm to young developing male minds?
How many times has this hypothesis been tested? Just once? Twice? Numerous times over several years? Or is this just one study, likely to be overturned by the next study as so many scientific studies are overturned?
How biased were the researchers? Was it a blind comparison or did they know before they accumulated the results which scan belonged to which person? Or which group? Or which gender?
The article answers some of the basic questions. The sample size was 116 people, 57 male and 59 female. The age breakdown wasn’t given, but it was stated that they were “healthy adults younger than 50 years of age”. The measurements were adjusted to “allow for the difference between men and women in physical size” — though I wonder if that means if they allowed for individual size differences, or imposed one size as the “normal” male size and another as the “normal” female size. The only other information mentioned is that all of the subjects were right-handed. Nothing mentioned about social background, race, or any other factor that may have contributed to socalization factors in brain development.
Kalinara raised another important question (one I wouldn’t have thought to ask, personally) [formatted from an IM conversation]:
Did they record anything about diet? Because diet’s been known to effect brain development and chemistry…at least according to a study. 😛
[D]iet’s a big thing. In a lot of “primitive” societies, there are foods that promote aggressive behavior that only the men eat…if they eat it while growing up…would that effect the size. So if we don’t know what all these people eat, it’s hard to say.
I looked up the study and came across this article which links to the full study here (click on the Full Text (PDF) link to see the study). There may or may not be a link between this issue and the UPenn study, but given that they are both interested in aggression I would say that the lifetime diet of the UPenn participants is defiintely something that could have affected the study.
III. The Layers of Interpretation
The finding itself was that MRI scans revealed that “women’s brains had a significantly higher volume of orbital frontal cortex in proportion to amygdala volume than did the brains of the men.” This is what I’d call the “empirical data” of this study, although even that cannot be confirmed until the study is reproduced by other teams and hopefully with some larger sample sizes. Still, this data is the objective findings of this particular study. From here, several layers of interpretation are created, some of which are built upon themselves.
The amygdala is involved in emotional behavior related to arousal and excitement, while the orbital frontal region is involved in the modulation of aggression.
If you’re wondering why this is under the “interpretation” heading, that’s because it’s a correlational behaviour. It’s presented as fact here, and the article itself states that the above data has come from “established scientific findings”. If this interpretation was a mere hypothesis I would be surprised. Because the assumption the amygdala and the orbital frontal regions influence arousal, excitment, and agression is the entire basis for the interpretations that follow. And, really, I have no problem assuming that — at least until proven otherwise — it’s true that those parts of the brain influence what the study says that they do.
I just want to point out that in Greek medical science, it was given that women were prone to having their womb wander around their bodies. Sure, our technology is better than back then, but it’s important to keep in mind that emotional reactions are notoriously hard to measure with accuracy. Which is not to debunk this interpretation, but rather to recommend a cautious, versus wholehearted, acceptance of it.
This study affords us neurobiological evidence that women may have a better brain capacity than men for actually ‘censoring’ their aggressive and anger responses.
While the Interpretation 1 was one of the foundational variables for the study, Interpretation 2 is based on the outcome. Assuming the accuracy of Interpretation 1, Interpretation 2 is a logical conclusion based on the empirical data.
But, as Jenn points out on Ragnell’s thread, bigger doesn’t always mean better [emphasis mine]:
First of all, the conclusion drawn (a sex difference in emotional control) is not directly addressed — what was actually found was, boiled down, that the women surveyed had a significantly larger amygdala then men. That, itself, may not mean anything — any conclusion towards emotional control is based upon the assumption that increased tissue size leads to greater tissue function. In fact, in the brain, function is correlated to complexity of neural tissue (e.g. folding of the cerebral cortex), not just size. Although having more tissue might mean you have greater function, this may not be the case. The authors, themselves, note in the discussion that they haven’t measured the complexity of the tissue, and further research must be done to characterize what exactly makes up for this increase in tissue, affecting whether or not this indicates a functional difference.
I’d also like to draw attention to the qualifiers that are used in Interpretation 2: That the study is evidence (not proof) “that women may” (again, not proven) “have a better brain capacity than men” (capacity is potential, which does not always correlate to the actuality of the issue). It is important to note that these words are emphasizing the tenuous nature of the links; putting the hypothesis out there but not claiming that their study “proves” such a thing.
Because men and women differ in the way they process the emotions associated with perception, experience, expression, and most particularly in aggression, our belief is that the proportional difference in size in the region of the brain that governs behavior, compared to the region related to impulsiveness, may be a major factor in determining what is often considered ‘gendered-related’ behavior
Again, I’d just like to point out that Interpretation 3 depends on the accuracy of Interpretations 1 and 2 (the whole idea of layered interpretations). I don’t believe that it compromises the potential usefulness of the study, or even of these particular interpretations, but rather that we — as the people who use the study — need to be aware of how the interpretations build on each other, and that interpretations like 3 are farther away from the emperical data than, say, Interpretation 1.
I’d also like to address the conclusion drawn by Gur, who I should point out tempers it with the word “belief”, that this is a major factor in determining “gender related” behaviour. This is the opinion of Gur, who is representing his team. It is the team’s interpretation, and the team’s bias, and when he says that it is their “belief” he is acknowleding that. But it’s not enough for him to acknowledge it, we need to as well. Could he be right? Of course. But he could also be wrong.
Turning to Jenn’s comment once again:
Secondly, the brain is a wonderfully fluid organ. Regions of the brain can shift its connections compared to degrees of use. *If* it is found that women have greater emotional control due to increased amygdala tissue, this may not indicate a genetic or biological difference so much as an adaptation to increased use.
The empirical data of this study measures only the ratio of the two parts of the brain that we currently believe are linked to certain emotions and the ability to control aggression. It is possible that female brains are naturally better suited to developing the parts of the brain that regulate this stuff. It’s also possible that levels of testosterone play a role. But it’s also possible that women’s brains tend to develop this control because women in American society are encouraged to repress their aggression more than men are.
Not only is the “nature versus nurture” debate far from settled in the scientific community, but there’s no rule saying that all of the above can’t play a role. It doesn’t have to be nature or nurture. But, even then, it’s important to remember that modern science doesn’t give us the evidence for this — deciding whether something is nature, nurture, or both is completely up to our own interpretation of the data.
Embracing your Inner Skeptic doesn’t mean disbeliving every study you come across. It doesn’t mean that we should never use studies to back up our opinions. What it does mean is turning a critical and — dare I say it? — skeptical eye to everything that we encounter. Studies we like, studies we don’t, news articles… there is always something to be gained from asking questions and separating interpretation from data. Science is possibly one of the most useful tools at our disposal, which makes it that much more important for us to be on our toes when its used by us or others.
(Hat tip to Jenn for doing the footwork in finding the original UPenn study.)