The Impact Of Personal Belief On Bayesian Reasoning

In recent years, the psychology of reasoning has transformed from the previous binary logic paradigm(true or false) to Bayesian probability paradigm.Unlike the prior paradigm which pays attention to the understanding of the connotation and extension, Bayesian reasoning is more emphasis on the uncertainty of human reasoning. According to Bayes’ theorem, people should combine the base rate with new evidence to calculate the posterior probability.The research of Bayesian reasoning, however, found that people always ignore the base rate. This paper conduct three experiments to study the influences of personal belief in Bayesian reasoning,the experiment divides the information into based on the belief and based on data.Experiment 1: base ratio and likelihood ratio are both based on belief. Experiment 2:base ratio based on the data, while likelihood ratio based on belief. Experiment 3: in contrast to the experiment 2, base ratio is based on the belief, and likelihood ratio is based on data. Then regression analyses were conducted to calculate the relative influence of the two pieces of information on Bayesian reasoning. results show that both base ratio and likelihood ratio significantly impacted participants’ Bayesian reasoning.Moreover, the information based on the belief significantly larger than the one based on data.