Short abstract (98 words). 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 humans’ exceptional dependence on communication and 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. (shrink)

People differ in the size of their social network, and thus in the properties of the linguistic input they receive. This article examines whether differences in social network size influence individuals’ linguistic skills in their native language, focusing on global comprehension of evaluative language. Study 1 exploits the natural variation in social network size and shows that individuals with larger social networks are better at understanding the valence of restaurant reviews. Study 2 manipulated social network size by randomly assigning participants (...) to learn novel evaluative words as used by two versus eight speakers. It replicated the finding from Study 1, showing that those exposed to a larger social network were better at comprehending the valence of product reviews containing the novel words that were written by novel speakers. Together, these studies show that the size of one's social network can influence success at language comprehension. They thus open the door to research on how individuals’ lifestyle and the nature of their social interactions can influence linguistic skills. (shrink)

People commonly believe that they communicate better with close friends than with strangers. We propose, however, that closeness can lead people to overestimate how well they communicate, a phenomenon we term the closeness-communication bias. In one experiment, participants who followed direction of a friend were more likely to make egocentric errors—look at and reach for an object only they could see—than were those who followed direction of a stranger. In two additional experiments, participants who attempted to convey particular meanings with (...) ambiguous phrases overestimated their success more when communicating with a friend or spouse than with strangers. We argue that people engage in active monitoring of strangers’ divergent perspectives because they know they must, but that they “let down their guard” and rely more on their own perspective when they communicate with a friend. (shrink)