What decision time can—and cannot—tell us about generosity

A person deciding how to share money may weigh their own payoff against what others receive. Does a quick decision favor self-interest, or can concern for others be immediate? Research has produced mixed answers, and a new laboratory study asks whether the answer varies with people's tendency to consider another person's point of view.

In a preprint, Enrico D'Ecclesiis and colleagues report that the association between decision time and sharing differed according to a self-reported measure of perspective taking. Among people scoring relatively high on that measure, longer times on the final choice screen were associated with slightly less prosocial allocations. Among those scoring relatively low, the estimated association went in the opposite direction, but was not statistically distinguishable from zero.

The finding is about an association between participants, not what would happen if the same person were made to decide more slowly. The researchers did not manipulate decision time or perspective taking, and they did not directly observe the mental steps behind each choice.

A choice with real payoffs

The experiment involved 652 participants at a laboratory in Venice. Most were students, and their average age was about 22. Each participant chose one of three ways to distribute 96 experimental points among four anonymous group members. One person in each group was randomly selected, and that person's choice determined everyone's payoff.

The options involved a trade-off. In the most self-regarding allocation, the selected decision-maker received 30 points; in the most prosocial allocation, they received 24. The latter option reduced inequality and increased both the minimum payoff and the average payoff of the other three members. For a selected decision-maker, the six-point difference was worth 18 euro cents. An intermediate option sat between the two.

Keeping the total at 96 points meant that a more prosocial choice did not create more points for the group as a whole. But the design cannot tell whether someone chose it because they wanted greater equality, cared about others' payoffs, or had another distributional motive: those features changed together.

After the allocation game, participants completed a five-question Cognitive Reflection Test, which rewards correct answers to reasoning problems that can invite an initially tempting wrong answer. They also completed an empathy questionnaire. The researchers used its perspective-taking questions to measure how strongly participants reported a tendency to adopt others' viewpoints. Because both measures came after the game, the authors cannot rule out effects of that task or its position in the sequence on later responses.

Two ways to study processing

The researchers compared the questionnaire scores and choices with two different indicators. One was performance on the reasoning test. The other was time spent on the final allocation-choice page, used as an imperfect indicator of processing during that particular decision.

Timing data were unavailable for five experimental sessions, leaving 525 people in the response-time analysis. Participants had already seen the options and answered comprehension questions before reaching the final screen, so the recorded time did not capture all the time they could have spent considering the choice.

The researchers coded the three allocations from 1 to 3, with higher scores representing the more prosocial options. In their model with demographic and social controls, at a perspective-taking score one standard deviation above the sample mean, an extra 10 seconds on the final screen was associated with a 0.040-point lower allocation score. At one standard deviation below the mean, the estimated association was 0.047 points higher per 10 seconds, but the uncertainty was large enough that the estimate was not statistically distinguishable from zero. The difference between the high- and low-perspective-taking associations was statistically significant.

The team did not detect a comparable interaction between perspective taking and performance on the Cognitive Reflection Test. That remained true when they restricted the comparison to participants with timing data. A null result does not establish that general analytic reflection is irrelevant; smaller associations may have gone undetected.

An interpretation, not a mental transcript

The authors suggest that people who readily consider others' perspectives might recognize the consequences for others early, while additional processing could bring the personal cost of sharing into focus. For people lower on perspective taking, they suggest, extra processing might instead bring others' outcomes to mind. These are possible explanations, not processes measured by the experiment.

A longer response can also reflect difficulty, conflict, preference strength or information search. The response-time analysis was not included in the study's preregistration. Although the main interaction persisted in several sensitivity checks, an alternative test accounting for the limited number of sessions produced p-values above the conventional 5% threshold.

The study therefore offers a reason to examine differences between people and between measures of reflection, rather than a prescription to make decisions faster or slower. Testing the proposed mechanism would require experiments that change decision conditions and measure more directly what participants attend to.