James Elander Irrational optimism is difficult to demonstrate for a particular individual, because it involves judgements about the probability of future events. It can however be demonstrated for groups of people. If most people in a group consider their chances of experiencing a future illness to be less than average, they cannot all be right, and on average they must be unrealistically optimistic. Optimistic biases , unrealistic optimism and comparative optimism all refer to ways in which people consider themselves to be less likely to experience negative events, and more likely to experience positive events, than they consider other people to be. Or they might be due to motivational factors, like the need to enhance self-esteem or reduce anxiety.
Optimistic biases have a number of potential benefits.
An important potential disadvantage of optimistic biases, however, is that in areas like health psychology they may make it less likely that individuals adopt self-protective behaviour . It is not absolutely clear, though, that there really are direct relationships between optimistic biases and actual health behaviours. Some psychologists claim that optimistic biases arise to some extent because of the way that situations are presented to participants in studies of this phenomenon. These included how desirable, how probable and how controllable the events were perceived to be, how closely related they were to participants personal experience, and whether a stereotype existed of the type of person to whom the event was likely to happen to. Optimistic biases were present when people rated their likelihood of RTA involvement as a driver, but not when they made ratings as a passenger.