Robyn Dawes defines irrationality as adhering to beliefs that are inherently self-contradictory, not just incorrect, self-defeating, or the basis of poor decisions. Such beliefs are unfortunately common. Witness two examples: the belief that child sexual abuse can be diagnosed by observing symptoms typically resulting from such abuse, rather than symptoms that differentiate between abused and non-abused children; and the belief that a physical or personal disaster can be understood by studying it alone in-depth rather than by comparing the situation in which it occurred to similar situations...