Research into decision-making under uncertainty showed that the rational subjective expected utility models which presumes that a good or 'rational' decision maker will sum the utilities and choose the action with the greatest total utility, does not explain how people make decisions [27, 28] . Kahneman and Tversky's research confirmed findings from the subjective perception of risk and further contributed to an understanding of how information about risks or uncertainties of outcomes influences decisions [27, 28] . Using hypothetical scenarios, studies have shown that people consistently underestimate risks of familiar and frequent events and overestimate the occurrence of low probability, but high consequence risks. Thus, rare events are perceived as more likely to occur than they do and common events are thought to occur less often than they do. The classic problems devised by Kahneman and Tversky involved asking subjects to choose between the certainty of saving 200 out of 600 lives or taking a 1 in 3 chance of saving 600 lives. They found that people's responses to possible negative outcomes are more extreme than their responses to possible positive outcomes. People also demonstrate a tendency to believe that their own risks are less than others, particularly if they believe that their exposure to risk is in some way under their control [31] . The impact of this tendency, described as unrealistic optimism and/or the illusion of control, is to reduce the perceived need to take protective measures [32] .