Thinking simply

Vaughan Bell has a nice piece in the Guardian on folk psychology – how ordinary people tend to think about their own thinking: “Our brains, and how they’re not as simple as we think”. This is a very important concept in the study of the evolution of human cognition, because how we think about our brains today may have little to do with the reasons why they changed over time.

For example, a great deal of psychology research has shown that we tend not to have a good insight into why we make certain choices. In one of the many studies in the area, Lars Hall and colleagues gave people a survey about their moral beliefs but used sleight of hand to change the choices they had originally made. When asked to justify the beliefs they hadn't endorsed, more than two-thirds of people didn't notice the switch and happily gave reasons for why they supported the opposite of their original position. Folk psychology tells us that we can accurately explain our actions and, consequently, many people think that these well-validated psychological effects never apply to them or simply don't exist. Suggesting that someone may not fully know their own actions and that their post-event justifications might be improvised simply won't wash in everyday conversation.

This is a phenomenon where psychology affects how we do scientific reasoning. I was doing this with my graduate students this morning – taking the opposite pattern of data and explaining it as a function of the same evolutionary hypothesis. It’s all too easy to justify post hoc a pattern by explaining it in terms of well-understood assumptions.