Numeracy, numeric attention, and number use in judgment and choice

Abstract

People higher (vs. lower) in objective numeracy—the ability to use probabilistic and mathematical concepts—use numeric information more when making decisions. Specifically, they are more sensitive to numeric levels than the less numerate and use more numeric versus nonnumeric information. Greater attention to numbers may explain this effect, but little is known about objective numeracy's relation to numeric attention and possible subsequent effects on choice. Therefore, we investigated whether numeracy is related to greater attention to numbers and greater use of numbers in consumer judgments and choices. Crucially, we tested whether numeric attention mediated number use in choices. In three experiments, we provided participants with information about different consumer products (e.g., dishwasher). Participants received either numbers-only or both numbers and verbal information. In Study 1 (N = 548), participants were asked to rate product attractiveness. In Studies 2a and 2b (N = 187 and 399), participants instead chose between product pairs. Attention was recorded using Mouselab. Greater objective numeracy was not related to sensitivity to numbers, but it was related to using numeric (instead of verbal) information more when making choices. The association of numeracy and attention was inconsistent across studies, although a meta-analysis combining the studies revealed a weak but significant relation between numeracy and frequency of attending to numbers. This attention variable mediated the association of numeracy and number use in the more powered Study 2b (but not 2a). Our research highlights the potential of considering attention when studying numeracy and provides insights for designing decision aids.