Years, Months, and Days versus 1, 12, and 365: The Influence of Units versus Numbers

Quantitative changes may be conveyed to consumers using small units (e.g., change in delivery time from 7 to 21 days) or large units (1-3 weeks). Numerosity research suggests that changes are magnified by small (vs. large) units because a change from 7 to 21 (vs. 1-3) seems larger. We introduce a reverse effect that we term unitosity: changes are magnified by large (vs. small) units because a change of weeks (vs. days) seems larger. We show that numerosity reverses to unitosity when relative salience shifts from numbers to units (study 1). Then, arguing that numbers (units) represent a low-level (high-level) construal of quantities, we show this reversal when mind-set shifts from concrete to abstract (studies 2-4). These results emerge for several quantities-height of buildings, time of maturity of financial instruments, weight of nutrients, and length of tables-and have significant implications for theory and practice.