Adaptive Rationality, Biases, and the Heterogeneity Hypothesis

Adaptive rationality theorists question the manner in which psychologists have typically assessed rational behavior and cognition. According to them, human rationality is adaptive, and the biases reported in the psychological literature are best seen as the result of using normative standards that are too narrow. As it turns out, their challenge is also quite controversial, and several aspects of it have been called into question. Yet, whilst it is often suggested that the lack of cogency comes about due to the implausibility of the alternative normative framework, in this paper I articulate a different strategy to resist the revolutionary rhetoric of AR. As I argue here, even if we accept the normative framework of AR, the challenge from AR is less damaging than usually accepted. In particular, I challenge the claim that biases reported in the literature should be conceived of as violations of axiomatic rationality. I argue that the category of bias refers instead to a range of heterogeneous phenomena and that, since several important families of biases are not just violations of axiomatic rationality, these are not vulnerable to the AR challenge. In fact, I also show that the families I consider here look like plausible cases of irrational behavior from the perspective of AR, and that the outcome of my analysis does not sit well with AR theorists’ claim that people are generally successful at achieving prudential and epistemic goals.