Abstract
Empirical validity of the prototypicality concept in the study of lie detection. The study of social knowledge and its influence on the behaviour of individuals has been guided, to some extent, by the idea that this knowledge is grouped in categories, the elements of the category being grouped around a prototype that summarizes and represents its meaning. This prototype, which elude unified theoretical definition, is operatively defined on the basis of external judgements about the degree of fit or belonging of the elements of the category (Rosch, 1978). This empirical definition of protypicality has permitted the control of its effects on dependent variables used as measures in psychology research, among them the time necessary for making judgements on the elements making up the category. The objective of the present study is to examine the empirical validity of the concept of prototypicality in the field of the detection of lying. In accordance with this objective, we have explored the organization of social knowledge about lying and the classification of messages according to their degree of prototypicality. In the second study, we have controlled the effects of the prototypicality of messages on the direction of judgements and the time taken by inexpert judges to decide whether the messages of unknown people are true or false. In support of our hypothesis, results obtained show that a) the more prototypical the message, the more believable it is, and b) the less time is used to make a judgement on it.
