Sharing with a stranger: people are more generous with time than money

ABSTRACT

With the present study, we tested whether generosity changes dependent on money or time being shared. During the experiment, participants N = 371 (MAge = 37.5 years, 38.8% female) completed questionnaires measuring social value orientation, moral identity centrality, and honesty-humility. The opportunity cost of time spent on a real effort task was measured with an incentivized method. Then, participants played two versions of a dictator game: either in a standard dictator game, where participants could share payoffs from the real effort task; or in a time dictator game, where participants decided how long they want to work for another participant’s payoff. We tested three hypotheses. (a) Time and money are not equivalent, and participants are more generous with time than with money. (b) Giving time results in higher positive affect than giving money. (c) Participants’ social value orientation, moral identity centrality, and honesty-humility explain the difference between the donations of time and money, and personality traits will have a stronger impact on time decisions than on monetary decisions. We found that approximately 50% of participants were more generous when giving time, this effect was not dependent on the opportunity cost of time. We think that our experiment is the first experiment to unambiguously show this effect. Furthermore, generosity was not related to positive affect and we found no moderating effect of personality traits.

KEYWORDS:

• Social preferences
• social value orientation
• allocation decisions
• time is money
• interpersonal choice
• individual differences

Acknowledgments

We thank Erik de Kwaadsteniet, Chris Reinders Folmer, Welmer Molenmaker and Rene Bekkers who reviewed the submission in stage 1 and provided critical and constructive feedback. Finally, we thank Stefanie Müller of the ZPID for her support during the data collection.

Changes from the Preregistration

As agreed with the editor we made changes in the introduction to improve the clarity of the purpose of the study and changes did not affect Hypothesis, Design and Methods. A detailed account of all changes (Introduction, Method and Analysis) can be found in the electronic supplement “Changes_from_prereg.docx”. All changes in the methods were approved by the editor.

Data Availability Statement

All materials including the, analysis scripts, instructions and experimental materials, and the data sets are available online. The preregistration, power analysis protocol and the experimental material can be found here: http://dx.doi.10.23668/psycharchives.2780. The data can be found here: http://dx.doi.10.23668/psycharchives.3472. The analysis script can be found here: http://dx.doi.10.23668/psycharchives.3473. All analyses have either been preregistered or marked as exploratory. All deviations from the preregistrations are stated.

Disclosure statement

We confirm that there are no relevant financial or non-financial competing interests to report.

Notes

1. We are aware that a simulation of the necessary power could also be carried out using an F test for the difference in the adjusted R². However, information about the expected change in R² is even more scarce than information about the possible correlations. For this reason, we decided to use the convenient and less complex test. Furthermore, no standard procedure to estimate power for mixed-level models is available.

Additional information

Funding

The Journal Comprehensive Results in Social Psychology (CRSP) and the Leibniz Institute for Psychology Information (ZPID) provided the funding for the data collection.