Evans says that risk intelligence can be improved by repeatedly estimating the probabilities of a narrow range of events and getting feedback. He says that there are a number of psychological traits that inhibit risk intelligence — ambiguity intolerance (that is, reacting to ambiguity with feelings of uneasiness, discomfort, dislike, anger and anxiety that intrude on rational assessment); the need for psychological closure (the desire for an answer to a question — any answer, even the wrong one — rather than remaining in a state of confusion and ambiguity); the fallacy of worst-case thinking (transforming low-probability events into complete certainties whenever the events are particularly scary); the all-or-nothing fallacy (the tendency to think of proof, knowledge, belief in binary terms); behavioural finance heuristics such as the availability heuristic and wishful thinking (people with high risk intelligence see the world as it is, not the way they would like it to be).