I was fantasizing about pitting one of my characters against Hannibal Lecter (because I do that sort of thing) when I came out with an argument that rather surprised me. It went something like this:
When a psychologist is studying his patient, his only evidence are what the patient tells him about himself (drawn out by questioning) and the patient’s behavior. His only way to test any ideas he may have about the patient is to ask questions. But by asking questions, he necessarily plants ideas in the other person’s head, thereby changing the state of his mind. If a psychologist suggests a possible explanation, the patient will immediately take that explanation and see if it fits. And, since evidence can be found to fit any theory, he probably will, even if it has nothing to do with the real movements of his mind. The presence of a new idea itself encourages him to view his mind in light of the new idea. Therefore, in psychology the proposal of a theory alters the facts that are supposed to make up the theory.
Thus, psychology inevitably alters the the thing it studies while it’s studying it and can only study by changing it, meaning that, scientifically speaking, almost all psychological conclusions are worthless, because the very act of proposing them alters the facts they are meant to explain.
What do you think? Am I missing something here?
By the way, I don’t think psychology is practically worthless: I’ve benefited from counsellors and the like myself. What I am saying is that, as a theoretical or explanatory science, it has severe flaws. Psychology, as far as I can see, is in much the same state as medicine was in the Medieval period: a lot of the time it works, sometimes it doesn’t, we have no idea why and the explanations we do have are tenuous at best.