The effect of religious beliefs on a syllogistic reasoning task

The study reported here was designed to document the existence of belief bias in a syllogistic reasoning task. Belief bias is the tendency to regard as correct the conclusion of a syllogism to the extent that the conclusion is consistent with one's personal belief. The study was further designed to determine whether belief bias tends to be greater when the basis of the belief in question is religious training or religious conviction.;One hundred students completed a Belief Assessment Survey and a Syllogism Evaluation Survey. The Belief Assessment Survey required them to indicate the extent to which they believed each of 15 controversial statements, as well as the extent to which their belief with respect to each of these statements was founded on religious training or conviction. The Syllogism Evaluation Survey required them to rate the correctness of conclusions drawn from 15 syllogisms corresponding to the 15 belief statements.;The results of the study confirmed the existence of belief bias, in that students tended to evaluate as correct the conclusions of syllogisms which agreed with their beliefs. The results did not support the proposition that the magnitude of belief bias is related to the extent to which the beliefs in question were based on religious conviction.;Respondents also completed a demographic and background survey that contained a four-item scale measuring the respondents' perceptions of the importance of religion in their lives (religiosity). Results provided no support for the notion that belief bias would be related positively to self-rated religiosity.;Results were interpreted as indicating that the existence of strongly held beliefs does have the effect of biasing one's syllogistic reasoning ability. However, this effect is no greater when the beliefs are rooted in religious beliefs than when the beliefs are derived from other social, ethical or moral considerations.