Belief bias, logical reasoning and presentation order on the syllogistic evaluation task

Evans, Barston and Pollard, (1983) found that on the syllogistic evaluation task participants tended to endorse believable conclusions as being valid but reject unbelievable conclusions as invalid. A phenomenon known as "Belief Bias". Additionally, they collected verbal protocols from participants and established that this influence of belief was primarily associated with initial reference to the conclusions of these syllogistic arguments. In contrast, better logical reasoning was associated with initial reference to the premises. This experiment was designed to try to direct participants' anention to either the conclusion or the premises of a syllogistic argument with the intention of manipulating participants' logical reasoning ability and susceptibility to belief. The results reflected an inability to alter the influence of beliefs, but in one condition where the conclusion was presented prior to the premises, there was a successful reduction in participants' reasoning ability. The results are discussed with respect to the current theories of belief bias.