Equity or Efficiency? Impact of Completion Motivation on Prosocial Behavior Preferences

doi:10.3724/SP.J.1041.2025.2202

Abstract

Abstract:

In prosocial behavior, helpers often face a trade-off between equity and efficiency due to limited resources. Previous research has shown that individuals are prone to prioritize equitable resource distribution when faced with incompatibility between fairness and efficiency. This tendency indicates that helpers frequently overlook the efficiency of aid provided to a minority in favor of equal assistance to a large group. This study hypothesizes that when the efficiency of assisting a few individuals reaches 100%, helpers may be prompted by completion motivation, resulting in a change in their decision-making regarding equity and efficiency.

We conducted six experiments to validate our hypothesis. Experiment 1 (N = 194) examined individual prosocial decision-making preferences in situations where assistance could not be fully provided (non-completable situations; inefficient help for all) as opposed to situations where complete assistance could be provided for a few beneficiaries (completable situations; efficient help for minority). Experiment 2 (N = 115) explored how different levels of efficiency in options influence individual helping preferences in non-completable situations, thus controlling for potential confounding effects of preference for high efficiency. Based on the results of Experiments 1 and 2, Experiment 3 (N= 164) further explored the mechanisms underlying the differences in helping preferences in these scenarios, thereby highlighting the mediating role of relative completion motivation. To investigate the contextual boundaries of completion motivation in shaping prosocial behavior preferences, Experiment 4 (N= 168) employed a refined experimental design that categorized helping contexts into survival-related and development-related situations. Building upon these findings, Experiment 5 (N = 133) examined whether completion motivation could enhance donation behaviors in broader prosocial contexts not constrained by equity-efficiency trade-offs. Afterward, Experiment 6 (N = 123) was conducted to eliminate potential confounding effects of psychological ownership, thus strengthening the robustness of the observed relationship between completion motivation and prosocial behavior.

The six experiments revealed that when the difficulties of all of the beneficiaries could not be completely resolved, participants displayed a strong preference for equity. Conversely, when the difficulties of a few beneficiaries could be fully addressed, they showed a decreased inclination toward equity and an increased inclination toward efficiency (Experiment 1). This notable shift in decision-making was significantly mediated by individual completion motivation (Experiment 3), rather than by a general preference for higher-efficiency options (Experiment 2). Specifically, in non-completable situations, a high motivation for equity drove individuals to choose fair options. Conversely, in completable situations, an increased motivation for completion prompted more individuals to prefer efficiency options. Moreover, the stimulating effect of completion motivation on the preference for efficiency was observed solely in development-related helping contexts while proving ineffective in survival-related situations (Experiment 4). In addition, individual completion motivation had a significant positive influence on donation amounts in broader contexts where equity considerations were absent (Experiment 5), after controlling for potential confounding effects of psychological ownership (Experiment 6).

This study significantly enhances our understanding of the relationship between equity and efficiency in prosocial behavior by highlighting the critical role of completion motivation. The findings suggest that helpers are apt to prioritize equity when no one can benefit completely; however, they shift toward efficiency when some individuals can be fully assisted. These insights have practical implications for designing interventions aimed at promoting effective altruism, underscoring the importance of helping efficiency while considering the psychological motivations that influence individuals’ prosocial decisions.

Key words: Donation behavior, equity, efficiency, completion motivation

LI Weiwei, OU Minhua, KANG Zhiqiang, WEN Yuting, LIN Xueqing. (2025). Equity or Efficiency? Impact of Completion Motivation on Prosocial Behavior Preferences. Acta Psychologica Sinica, 57(12), 2202-2219.

Figures/Tables 6

Figure 1 The influence of help scenarios and the efficiency of efficiency-oriented options on help preferences: (A) The influence of help scenarios on individual help preferences (Study 1); (B) The influence of efficiency on individual help preferences in the non-completable situation (Study 2).

Figure 2 The influence of help scenarios on help preferences and motivation levels: (A) The influence of help scenarios on individual help preferences; (B) The influence of help scenarios on individual fairness motivation and completion motivation. ** p < 0.01

Figure 3 Mediating mechanism of help scenarioson individual help preferences.
Note. * p < 0.05, ** p < 0.01, *** p < 0.001

Figure 4 The influence of help scenarios and recipients' need on help preferences: (A) The influence of help completability on individual help preferences in the survival-related need situation; (B) The interaction effect of help scenarios and recipients' needs on individual help preferences.

Figure 5. Effects of presence of progress indicators on donation amounts and completion motivation: (A) The effect of presence of progress indicators on individual donation amounts; (B) The effect of presence of progress indicators on individual completion motivation and sense of responsibility. * p < 0.05, *** p < 0.001

Figure 6. Presence of progress indicators as a mediating mechanism for individual donation amounts. Note: *** p < 0.001

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