Dan Sperber

In their reviews, Chater and Oaksford, Dutilh Novaes, and Sterelny are critical of our modularist approach to reason. In this response, we clarify our claim that reason is one of many cognitive modules that produce intuitive inferences each in its domain; the reason module producing intuitions about reasons. We argue that in‐principle objections to the idea of massive modularity based on Fodor's peculiar approach are not effective against other interpretations that have led to insightful uses of the notion in psychology and biology. We explain how the reason module evaluates reasons on the basis of their metacognitive properties. We show how the module fulfils a social function, that of producing reasons to justify oneself and convince others and of evaluating the reasons others produce to convince us.

Reason, we are told, is what makes us human, the source of our knowledge and wisdom. If reason is so useful, why didn't it also evolve in other animals? If reason is that reliable, why do we produce so much thoroughly reasoned nonsense? In their groundbreaking account of the evolution and workings of reason, Hugo Mercier and Dan Sperber set out to solve this double enigma. Reason, they argue with a compelling mix of real-life and experimental evidence, is not geared to solitary use, to arriving at better beliefs and decisions on our own. What reason does, rather, is help us justify our beliefs and actions to others, convince them through argumentation, and evaluate the justifications and arguments that others address to us. In other words, reason helps humans better exploit their uniquely rich social environment. This interactionist interpretation explains why reason may have evolved and how it fits with other cognitive mechanisms. It makes sense of strengths and weaknesses that have long puzzled philosophers and psychologists--why reason is biased in favor of what we already believe, why it may lead to terrible ideas and yet is indispensable to spreading good ones.--

The spatial composition of human portraits obeys historically changing cultural norms. We show that it is also affected by cognitive factors that cause greater spontaneous attention to what is in front rather in the back of an agent. Scenes with more space in front of a directed object are both more often produced and judged as more aesthetically pleasant. This leads to the prediction that, in profile‐oriented human portraits, compositions with more space in front of depicted agents (a “forward bias”) should be over‐represented. By analyzing a large dataset (total N of 1,831 paintings by 582 unique identified European painters from the 15th to the 20th century), we found evidence of this forward bias: Painters tended to put more free space in front of, rather than behind, the sitters. Additionally, we found evidence that this forward bias became stronger when cultural norms of spatial composition favoring centering became less stringent.

Reasoning is generally seen as a means to improve knowledge and make better decisions. However, much evidence shows that reasoning often leads to epistemic distortions and poor decisions. This suggests that the function of reasoning should be rethought. Our hypothesis is that the function of reasoning is argumentative. It is to devise and evaluate arguments intended to persuade. Reasoning so conceived is adaptive given the exceptional dependence of humans on communication and their vulnerability to misinformation. A wide range of evidence in the psychology of reasoning and decision making can be reinterpreted and better explained in the light of this hypothesis. Poor performance in standard reasoning tasks is explained by the lack of argumentative context. When the same problems are placed in a proper argumentative setting, people turn out to be skilled arguers. Skilled arguers, however, are not after the truth but after arguments supporting their views. This explains the notorious confirmation bias. This bias is apparent not only when people are actually arguing, but also when they are reasoning proactively from the perspective of having to defend their opinions. Reasoning so motivated can distort evaluations and attitudes and allow erroneous beliefs to persist. Proactively used reasoning also favors decisions that are easy to justify but not necessarily better. In all these instances traditionally described as failures or flaws, reasoning does exactly what can be expected of an argumentative device: Look for arguments that support a given conclusion, and, ceteris paribus, favor conclusions for which arguments can be found.