"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. We therefore test whether age differences in numeracy performance are mediated by a reduced motivation to think hard about complex problems—as measured by need for cognition. Method. We recruited an age-diverse convenience sample of 306 UK adults. They completed measures of numeracy and need for cognition. They self-reported their educational attainment and other demographics. Results. Older age was related to lower numeracy and lower need for cognition. The negative relationship between age and numeracy was mediated by need for cognition. These findings held after we controlled for educational attainment and other demographic factors. Discussion. Older adults may show lower numeracy performance due to lack of motivation. We discuss strategies for improving people’s motivation to complete numeracy measures and other numerical tasks.