Chang, L. W., et al. (2024).
PNAS, 121(46).
Abstract
People often rely on numeric metrics to make decisions and form judgments. Numbers can be difficult to process, leading to their underutilization, but they are also uniquely suited to making comparisons. Do people decide differently when some dimensions of a choice are quantified and others are not? We explore this question across 21 preregistered experiments (8 in the main text, N = 9,303; 13 in supplement, N = 13,936) involving managerial, policy, and consumer decisions. Participants face choices that involve tradeoffs (e.g., choosing between employees, one of whom has a higher likelihood of advancement but lower likelihood of retention), and we randomize which dimension of each tradeoff is presented numerically and which is presented qualitatively (using verbal estimates, discrete visualizations, or continuous visualizations). We show that people systematically shift their preferences toward options that dominate on tradeoff dimensions conveyed numerically—a pattern we dub “quantification fixation.” Further, we show that quantification fixation has financial consequences—it emerges in incentive-compatible hiring tasks and in charitable donation decisions. We identify one key mechanism that underlies quantification fixation and moderates its strength: When making comparative judgments, which are essential to tradeoff decisions, numeric information is more fluent than non-numeric information. Our findings suggest that when we count, we change what counts.
Significance
Across 21 experiments with over 23,000 participants in managerial, policy, and consumer contexts, we identify a critical distortion that shapes how people make decisions involving tradeoffs across qualitative and quantitative attributes. When making hiring, donation, and policy decisions, people tend to privilege quantitative information, favoring options that dominate on the dimension described numerically. This “quantification fixation” is driven by the perception that numbers are easier to use for comparative decision-making; people who are more comfortable with numbers—those higher in subjective numeracy—are more likely to exhibit quantification fixation. As quantification becomes increasingly prevalent, the comparison fluency of numbers may systematically skew decisions. These findings suggest that quantifying certain choice features can have important repercussions for how decisions are made.
Here are some thoughts:
For psychologists, this research underscores a critical insight: the act of quantifying information is not neutral. It shapes perception, distorts tradeoffs, and can lead patients to make choices that feel rational but may not align with their true values or well-being.
By recognizing quantification fixation, psychologists can become more effective guides—helping patients see beyond the numbers, appreciate qualitative dimensions of their lives, and make decisions that are not just data-driven, but meaning-driven.
In short, when we count, we change what counts. Psychologists have a vital role in ensuring that what should count—emotional truth, personal values, and human experience—is not lost in the numbers.
