Dual Processes and Training in Statistical Principles

A statistical training study is reported which demonstrates that analytic responding on everyday reasoning problems can be increased after instruction in statistical principles. Participants were given training on the Law of Large Numbers (Fong, Krantz and Nisbett, 1986). Bias was eliminated, but only on written justifications of their responses. Belief-based responding was still utilized when participants were asked for a quick indication of argument strength on a rating scale, thus demonstrating a dissociation between analytic and belief-based responding. Findings are discussed in terms of dual process theories of reasoning.