1. What is the function of reasoning?
On the one hand, it seems that the capacity to reason is a cognitive superpower which enabled Homo sapiens to gain an immense amount of knowledge that set our species far apart from the rest of the animal kingdom. On the other hand, there is robust evidence that people display seemingly irrational reasoning biases. How could this “flawed superpower” have evolved? What, if anything, is the adaptive function of reasoning?
A number of influential researchers in philosophy, psychology, and cognitive science have proposed that the human capacity to reason evolved for individuals to manipulate others through persuasion and self-justification. It is widely supposed that this view of reason renders confirmation bias (or “myside bias”) a feature rather than a bug, since such a bias helps the reasoner build a case in favor of their beliefs. In “The Evidence is Not on My Side: Reason, Evolution, and Bias” (completed draft) I show that what allows the view to explain myside bias is not the function of reason it posits, but rather the auxiliary hypothesis that in achieving this function it was cost-effective to offload to interlocutors the task of formulating counterarguments. I show that this explanatory strategy can be mimicked under rival views of the function of reason. For example, myside bias may have evolved to enable a division of argumentative labor that allowed groups to reach the truth efficiently, or to enable lone individuals to efficiently test their own beliefs by bringing to mind the grounds for those beliefs.
In “Cracking the Enigma: Cultural Knowledge, Social Learning, and Private Reason” (completed draft) I propose that the capacity to reason evolved for individuals to generate true beliefs for the purpose of solving novel problems in the environment. Drawing on ethnographic studies of hunter-gatherer societies, I argue that the fitness of individuals in the relevant ancestral environments was enhanced by reasoning taking as input rule-like cultural knowledge transmitted through stories.