People who are better at working with numbers also look at numbers more often

Tiede, K. E., Bjälkebring, P., & Peters, E. (2021). Numeracy, numeric attention, and number use in judgment and choice. Journal of Behavioral Decision Making. Advance online publication. https://doi.org/10.1002/BDM.2264

In our new paper, we found that people who score higher in numeracy, the ability to understand and use probabilities and numbers, look more often at numeric information when making judgments and decisions than those who are lower in numeracy.

In three studies, we provided participants with information about consumer products (e.g., a dishwasher). The information was either only numeric (e.g., 77 out of 100 points) or included both numbers and descriptive labels (e.g., “good”) (see Figure 1). Participants were then asked to rate the product’s attractiveness or to choose between two kinds of the same product. In all studies, we measured the information at which participants looked and for how long they looked.

Figure 1. Screenshot of the choice task in Studies 2a and 2b: Participants had to hover their mouse cursor over a box to see the covered information. The respective label for the 71-point rating was “good”.

Across all studies, there were three key findings:

1. We found that people higher in numeracy looked more often (but not longer) at numeric information than those with lower numeracy when combining the data of all three studies.

2. We replicated previous findings that people higher in numeracy relied more strongly on numeric information than their less numerate counterparts. Importantly, numeric attention could statistically explain the relationship between numeracy and number use in one of the two studies that tested this relation. Specifically, people higher (vs. lower) in numeracy looked more often at numbers. This increased numeric attention, in turn, was related to an increased use of numeric information.

3. Finally, our studies also demonstrated that numeric attention is driven specifically by numeric abilities rather than general intelligence or the subjective preference for numbers (i.e., subjective numeracy).

Our results help to understand how numeracy affects judgment and decision making and to design decision aids to improve the decisions of people both lower and higher in numeracy.

To learn more about numeracy and decision making, check out:

Peters, E. (2020). Innumeracy in the wild: Misunderstanding and misusing numbers. Oxford University Press. Named a New Books Network podcast book of the day, https://newbooksnetwork.com/innumeracy-in-the-wild and featured by Oxford University Press as on the frontiers of psychology research.