IQ and bias

An excerpt from a 2008 paper by Stanovich and West:

The framework in Figure 1 illustrates why rationality will not be uniformly related to intelligence. Instead, that relationship will depend upon the degree that rational responding requires sustained cognitive decoupling. When the heart of the task is recognizing the need for heuristic override but the override operation itself is easily accomplished, no sustained decoupling is necessary and rational thinking will depend more on the operations of the reflective mind than on those of the algorithmic mind (Stanovich, 2008a, 2008b). Thus, relationships with intelligence will be attenuated. Additionally, as Kahneman (2000) has argued, when detecting the necessity for override is very difficult (Parameter 2 is low), performance overall will be quite low and no relationships with cognitive ability will be evident.

In other words, smarter people can be less biased— but only when they're paying attention to the relevant biases.