Experiments on genetic risk perception and decision making: explorative studies.

In cognitive psychology, considerable attention has recently been given to studies on risk perception and decision making under uncertainty. The attempt to apply the cognitive frameworks to the genetic counseling setting is a major challenge. After reviewing the relevant literature in cognitive psychology, the aim of our first study was to understand how people process and memorize genetic information about Huntington's disease. Although we did not obtain clear-cut data about the mental representation of this genetic information in our subjects, the context in which the information was given was a surprisingly strong variable affecting its memorability. Pauker and Pauker (1979) developed a tree model helping the prospective parents to use the probabilities as well as the costs of different outcomes to decide on having an amniocentesis performed. Specific attention was paid to the estimation of the costs of the outcomes. While repeating the same experiment, the goal of our second study was to investigate whether the subjects agree with the advice given by the model and whether their final decision was affected by using the technique or not. In a third experiment, we scrutinized the joint decision process of two persons as compared with the decision process of people not discussing together. They all received genetic information, either about Hemophilia or about Down syndrome. The joint decision process was completely different for the two genetic diseases. As the two diseases have highly different risk probabilities, we had to unravel the influence of the importance of the risk and the burden of the disease on the ongoing decision of two persons. The set of findings at least suggests that the existing models in the literature have overlooked the importance of the context in providing the information and the complexities of the decision process when two people have to agree. Moreover, the serious problems in carrying out an experiment when a decision tree is imposed upon the subjects, reveal the potential inadequacy of the assumed total rationality of the decision maker.