Reasoning from unfamiliar premises: a study with unschooled adults

A long tradition of research initiated by Luria in the 1930s has established that unschooled adults perform poorly on reasoning tasks. Particularly when the premises are unfamiliar, they adopt an inappropriate empirical bias. However, recent findings show that young children with little or no schooling reason competently if prompted to think of the unfamiliar premises as pertaining to a distant planet. We tested two groups of adults: illiterate, unschooled adults and adults with limited schooling. Both groups received problems that included either a premise with unknown content or a premise contradicting their everyday experience. When given a minimal prompt, both groups manifested the customary empirical bias. By contrast, when explicitly prompted to think of the unfamiliar premises as pertaining to a distant planet, they reasoned accurately and appropriately justified their conclusions in terms of the supplied premises.