Kaj_Sotala summarizes fascinating ideas from Keith E. Stanovich’s What Intelligence Tests Miss: The Psychology of Rational Thought
Cognitive science suggests that our brains use two different kinds of systems for reasoning: Type 1 and Type 2. Type 1 is quick, dirty and parallel, and requires little energy. Type 2 is energy-consuming, slow and serial. Because Type 2 processing is expensive and can only work on one or at most a couple of things at a time, humans have evolved to default to Type 1 processing whenever possible. We are “cognitive misers” – we avoid unnecessarily spending Type 2 cognitive resources and prefer to use Type 1 heuristics, even though this might be harmful in a modern-day environment.
Stanovich further subdivides Type 2 processing into what he calls the algorithmic mind and the reflective mind. He argues that the reason why high-IQ people can fall prey to bias almost as easily as low-IQ people is that intelligence tests measure the effectiveness of the algorithmic mind, whereas many reasons for bias can be found in the reflective mind. An important function of the algorithmic mind is to carry out cognitive decoupling – to create copies of our mental representations about things, so that the copies can be used in simulations without affecting the original representations. For instance, a person wondering how to get a fruit down from a high tree will imagine various ways of getting to the fruit, and by doing so he operates on a mental concept that has been copied and decoupled from the concept of the actual fruit. Even when he imagines the things he might do to the fruit, he never confuses the fruit he has imagined in his mind with the fruit that’s still hanging in the tree (the two concepts are decoupled). If he did, he might end up believing that he could get the fruit down by simply imagining himself taking it down. High performance on IQ tests indicates an advanced ability for cognitive decoupling.
In contrast, the reflective mind embodies various higher-level goals as well as thinking dispositions. Various psychological tests of thinking dispositions measure things such as the tendency to collect information before making up one’s mind, the tendency to seek various points of view before coming to a conclusion, the disposition to think extensively about a problem before responding, the tendency to calibrate the degree of strength of one’s opinion to the degree of evidence available, the tendency to think about future consequences before taking action, the tendency to explicitly weigh pluses and minuses of situations before making a decision, and the tendency to seek nuance and avoid absolutism. All things being equal, a high-IQ person would have a better chance of avoiding bias if they stopped to think things through, but a higher algorithmic efficiency doesn’t help them if it’s not in their nature to ever bother doing so. In tests of rational thinking where the subjects are explicitly instructed to consider the issue in a detached and objective manner, there’s a correlation of .3 – .4 between IQ and test performance. But if such instructions are not given, and people are free to reason in a biased or unbiased way as they wish (like in real life), the correlation between IQ and rationality falls to nearly zero!
There is much more, all of it quite fascinating, in the rest of the article.