Same numbers, different meanings: How numeracy influences the importance of numbers for pro-social behavior

Numerical information often serves as a basis for evaluations, decisions and behavior. In requests for charitable giving, three numerical cues in the donation description are of particular importance: the number of potential recipients of a donation, the total number of people in need, and their proportion. In three studies, we examined the effects of numeracy on the weight given to these numerical cues in donations. Study 1 contrasted the importance of a higher absolute number (of potential recipients and the number of people in need) vs. a higher proportion of recipients. In Study 2, we investigated the effects of the total number of people in need and Study 3 was designed to focus on the impact of the absolute number of potential recipients. Our results revealed a consistent pattern demonstrating that highly numerate individuals were willing to donate more for projects that offered assistance to the greatest proportion of recipients. Conversely, less numerate individuals were insensitive to this proportion; they tended to donate more with increases in both the number of recipients and the total number of people in need. The meaning of numbers in donation decisions and the resulting motivation to help depends on numeric skill.

► We examine the effects of numeracy on pro-social behavior.
► In three studies we varied numerical cues in donation requests.
► Higher numeracy increases proportion dominance in donation decisions.
► Effectiveness mediates the effect of proportion on donations for high numerate individuals.