Communities of denialists grow by feeding on each other's emotional arguments and support. JK Rowling, author of the Harry Potter books, recently referred to this when she gave the commencement address at the annual meeting of the Harvard Alumni Association on "The fringe benefits of failure and the importance of imagination." She said that "choosing to live in narrow spaces leads to a form of mental agoraphobia, and that brings its own terrors." Finally, research has shown that "evidence, including authoritative corrections that contradict strongly held views, can paradoxically reinforce those views." Thus people who are exposed to evidence that contradict their own biased views are less likely to change their views than those not exposed. The precise neuro-psychological explanation for this is not known but must have something to do with our self-perceived status as moral, intelligent human beings.