One of the regular web comics I read, Saturday Morning Breakfast Cereal, posted this cartoon today:
I think the thing I appreciate about SMBC is that it takes complex topics, often psychological in nature, and presents them in a concise, funny way. And it's true, humans have a unique ability (unique as far as we know, anyway) to explain their own behavior. And countless psychological studies have demonstrated those explanations are often wrong.
One of the criticisms of behaviorism is that it oversimplifies behavior, because though we respond to rewards and punishments, the ability to think through those contingencies alters our response. And yet, again and again, researchers have taken complex human behavior and been able to shape something like it in animals, only through reinforcements and punishments, such as, for instance, the superstitious pigeons. This is why many behaviorists argue that factoring in rationalization is adding unnecessary complexity, and the parsimonious approach would be to completely discount that. This was the radical approach Skinner took, and the reason he referred to cognitive psychology as the creationism of psychology.
As I've said before, I don't take the extreme approach of Skinner, and I do believe that cognition is important in understanding human behavior. At the same time, humans are really bad at knowing what is causing them to behave as they do. They seek out things they believe will them happy, not realizing that their happiness is unlikely to be permanently affected by any thing, and that they're terrible at even knowing what will actually make them happy. They make poor decisions, and offer convoluted explanations that fit them into a neat, coherent narrative, even if it means changing the story to contradict reality. They will even go so far as to change their own memories to make things fit their explanation. We feel emotions, often not knowing why, and ascribe them to whoever or whatever is around at that moment. And though we do these things ourselves, we're quick to recognize when others are thinking or behaving irrationally.
This is the reason I have to resist the urge to argue with others, vehemently, when they tell me psychology is just "common sense." Because as psychology has been demonstrating almost since the beginning, common sense is really not all that common or sensical.