This is clearly in contradiction with the expected utility
hypothesis in which a rational person is assumed to choose the option yielding the
highest average payoff. Adding the influence of variance constitutes one of the main differences with
the expected utility hypothesis for which variance is assumed not to influence the
decision of a rational individual. Their decision will wholly depend on the
probabilities of the part of the game in which they are involved. When developing their theory, Kahneman and Tversky set out a framework
which is still very useful to analyze the findings of behavioural finance. First
information is edited in order to simplify and quicken the second stage, the evaluation
process. This clearly contradicts the Expected Utility Theory where all information is
assumed to be evaluated in a rational and objective way. This is partly due
to the fact that the cognitive task of analyzing all information equally is hardly
possible. The result of this behaviour is that investors simplify the information in
order to evaluate it more easily. For example loosing a concert ticket and loosing the same
value of the ticket but in cash leads to different choices. This
is one reason why the followers of behavioural finance seriously doubt that
individuals are able to distinguish properly between causal and empirical
relationships.