"Thinking about numbers is not my idea of fun": need for cognition mediates age differences in numeracy performance.

Background: Numeracy refers to people's ability to use numbers. Low numeracy has been associated with difficulties in understanding risk-benefit information and making health decisions. Older adults tend to perform worse than younger adults on measures of numeracy, but some theories of aging suggest that older adults may lack motivation for such tasks.

Whose statistical reasoning is facilitated by a causal structure intervention?

People often struggle when making Bayesian probabilistic estimates on the basis of competing sources of statistical evidence. Recently, Krynski and Tenenbaum (Journal of Experimental Psychology: General, 136, 430-450, 2007) proposed that a causal Bayesian framework accounts for peoples' errors in Bayesian reasoning and showed that, by clarifying the causal relations among the pieces of evidence, judgments on a classic statistical reasoning problem could be significantly improved. We aimed to understand whose statistical reasoning is facilitated by the causal structure intervention.

When does information about causal structure improve statistical reasoning?

Base rate neglect on the mammography problem can be overcome by explicitly presenting a causal basis for the typically vague false-positive statistic. One account of this causal facilitation effect is that people make probabilistic judgements over intuitive causal models parameterized with the evidence in the problem. Poorly defined or difficult-to-map evidence interferes with this process, leading to errors in statistical reasoning.