Personal theories, intellectual ability, and epistemological beliefs: Adult age differences in everyday reasoning biases (original) (raw)

2000, Psychology and Aging

Age-related differences in everyday reasoning biases were explored. In each of 2 social domains, examination of theoretical beliefs and biases along 2 dimensions of scientific reasoning, involving the law of large numbers and the evaluation of experimental evidence, revealed that, across age groups, scientific reasoning was used to reject evidence that contradicted prior beliefs; relatively cursory reasoning was used to accept belief-consistent evidence. Biased reasoning was more common among middle-aged and older adults than among young adults. Dispositions to engage in analytic processing were negatively related to biases, but intellectual abilities and bias were not related. The findings support a 2-process view of adult cognitive development and suggest that the tendency to rely on heuristic information processing increases with age. The social and cognitive psychology literatures are replete with demonstrations of erroneous everyday reasoning (see Evans & Over, 1996; Stanovich, 1999). At the heart of many reasoning fallacies, miscues, and poor decisions lay networks of beliefs and personal theories. Although theories of the causal mechanisms in specific social domains (e.g., faith in God leads to salvation) have numerous adaptive functions (e.g., reducing cognitive load), overreliance on these belief systems interferes with the objectivity of reasoning and decision making. An understanding of the manner in which personal, "naive" theories influence reasoning is thus vital to the advancement of theories of everyday cognition, yet adult developmentalists have paid scant attention to the theoryreasoning relationship. Consider, for instance, an observer who believes that low socioeconomic status (SES) promotes laziness and that economic success is a product of intelligence. Told that a specific welfare recipient has not sought employment for several months, the adult accepts this evidence as proof that his or her theory is correct and does not examine the evidence for alternative explanations of the observed correlation (e.g., the unemployed party is disabled). Alternatively, presented evidence that a person became wealthy despite a low score on an intelligence test, the observer is likely to seek flaws in the evidence and to construct explanations that would render the correlation spurious (e.g., the assessment instrument is invalid) or anomalous (e.g., the intelligence-wealth belief cannot be discredited by a single observation).