Abstract

Are we gullible? Can we be easily influenced by what others tell us, even if they do not deserve our trust? Many strands of research, from social psychology to cultural evolution suggest that humans are by nature conformist and eager to follow prestigious leaders. By contrast, an evolutionary perspective suggests that humans should be vigilant towards communicated information, so as not to be misled too often. Work in experimental psychology shows that humans are equipped with sophisticated mechanisms that allow them to carefully evaluate communicated information. These open vigilance mechanisms lead us to reject messages that clash with our prior beliefs, unless the source of the message has earned our trust, or provides good arguments, in which case we can adaptively change our minds. These mechanisms make us largely immune to mass persuasion, explaining why propaganda, political campaigns, advertising, and other attempts at persuading large groups nearly always fall in deaf ears. However, some false beliefs manage to spread through communication. I argue that most popular false beliefs are held reflectively, which means that they have little effect on our thoughts and behaviors, and that many false beliefs can be socially beneficial. Accepting such beliefs thus reflects a much weaker failure in our evaluation of communicated information than might at first appear.