In discussion of science and the mind, there’s a line of thinking that goes like this: if everything is physical, then stuff like emotions and thought and the talk therapy of clinical psychology are downgraded. Last month I wrote a post for the Biology of Mind class weblog about dualists trying to use this view to argue against physicalism.

I’ve also come across arguments going in the opposite direction: the thought that the language of psychology can’t be scientific, that only the study of the mind grounded in neuroscience is legitimate. An example of this can be found in this interview with Barbara Oakley on Point of Inquiry. Give it a listen. Around the 15 min mark, you’ll get to hear Oakley talking about how malignant narcicism can’t be a legitimate psychological diagnosis, because we don’t have a lot of genetics or neuroscience on it. Then around the 18 min mark, you get to hear her going on about how the brains of psychopaths are different.

The problem here is that if physicalism is true, any difference in personality will be grounded in some brain difference. We obviously don’t know what these brain differences are in every case, because our neuroscience isn’t that advanced. This means, on the one hand, failing to find a genetic or neurological basis for something doesn’t mean it isn’t real. A better question to ask about diagnoses like “malignant narcissism” is whether the concept is predictive of anything–for example, does performance on a test for malignant narcissism predict behavior in other contexts? Do people classed as malignant narcissists tend to respond the same ways to the same treatments?

On the other hand, finding out that psychopaths are neurologically different than other people isn’t surprising anymore. Every mental difference should be grounded in some physical difference. It’s mainly the details we need to worry about now.