Researchers from the Modeling Animal Decisions team at the University of Bristol led by Professor John McNamara of Bristol's School of Mathematics have shown that human decision making that involves choice is not rational in research that was presented in the Jan. 14, 2014, edition of the Royal Society Journal Biology Letters.
The results of the study were based on a comparison of primate behavior in selecting food options and the similar behavior of people in selecting houses.
This is the first research that did not rely on the individual changing their minds about and option and the first that proves that two of the key principles of rationality, regularity and transitivity, are not necessarily a function of human choices nor are the two principles of rationality necessary for making the optimum choice for a given individual in a given situation.
Regularity can be considered equivalent to consistency. Transitivity is based on the idea that if a person has a choice of three items in which the third is preferable to the other two by direct comparison the person would rationally opt for the third choice.
Irrational behavior in humans can be attributed to an evolutionary inheritance of the same behavior in primates. Irrational behavior in humans is predicated on the optimal choice having some perceived advantage to the choice maker even if the perceived advantage is neither rational nor actually exists.