The overall effect of manipulating cognitive resources to promote the “intuitive” system at the expense of the “deliberative” system is very close to zero

Altruism, fast and slow? Evidence from a meta-analysis and a new experiment. Hanna Fromell, Daniele Nosenzo & Trudy Owens. Experimental Economics, February 25 2020. https://link.springer.com/article/10.1007/s10683-020-09645-z

Abstract: Can we use the lens of dual-system theories to explain altruistic behavior? In recent years this question has attracted the interest of both economists and psychologists. We contribute to this emerging literature by reporting the results of a meta-study of the literature and a new experiment. Our meta-study is based on 22 experimental studies conducted with more than 12,000 subjects. We show that the overall effect of manipulating cognitive resources to promote the “intuitive” system at the expense of the “deliberative” system is very close to zero. One reason for this null result could be that promoting intuition has heterogeneous effects on altruism across different subgroups of subjects or contexts. Another reason could be that there simply is no real effect and that previously reported single results are false positives. We explore the role of heterogeneity both by performing a mediator analysis of the meta-analytic effect and by conducting a new experiment designed to circumvent the issue of potential heterogeneity in the direction of the effect of promoting intuition. In both cases, we find little evidence that heterogeneity explains the absence of an overall effect of intuition on altruism. Taken together, our results offer little support for dual-system theories of altruistic behavior.

Discussion and conclusions

In this paper, our aim was to probe the validity of a dual-system approach to altruistic behavior, by testing the hypothesis that trade-offs between self-interest and altruism trigger a conflict between our “fast”, intuitive System 1 and our “slower”, more deliberative System 2. We performed a meta-analysis of the existing literature on the relation between altruism and intuition/deliberation and found that the manipulations used in previous experiments to promote the intuitive system at the expense of the deliberative system (using ego depletion tasks, cognitive load, time pressure or priming) have an overall effect on altruism that is very close to, and not significantly different from, zero.

Can this aggregate null result be due to the fact that the relation between altruism and our two systems is genuinely heterogeneous across different subgroups and decision situations, as some researchers have suggested? We find little evidence that this may be the case. We first run a mediator analysis based on the existing literature and consider a number of potential mediators of the relation between intuition and altruism (including mediators previously suggested in the literature, such as gender, the stakes of the experiment, or the frame of the task). We find that none of the mediators included in the analysis play a significant role in explaining the mixed results in existing studies. One possible exception is the frame of the task, for which we find evidence of a mediating effect in some specifications of the analysis, but not in others.

We then designed and ran a new experiment that allowed us to probe the validity of dual-system theories of altruism without being vulnerable to the presence of unobserved and/or unanticipated heterogeneity in the relation between altruism and intuition. We argue that, if trade-offs between altruism and self-interest trigger a conflict between the intuitive and deliberative systems, then being exposed to these trade-offs should be willpower-depleting. We do not find evidence that this is the case. Directionally, the effect is in line with the hypothesis: subjects who were exposed to trade-offs between altruism and self-interest perform worse on a task that requires willpower than subjects who were not exposed to such trade-offs. However, we cannot reject the null that the two groups perform similarly.Footnote 20

Overall, the combination of evidence from the meta-study and the new experiment suggests that choices that involve trade-offs between altruism and self-interest do not trigger any strong conflict between intuition and deliberation. This could be because, in the realm of altruistic behavior, the decision processes governed by the intuitive and deliberative systems may actually both lead to the same outcome for any given individual. That is, the two systems are not actually in conflict when it comes to making these type of decisions, and hence their outcome is the same. Alternatively, the null results reported in the literature and in our new experiment could mean that the lens of dual-system models does not extend to altruistic behavior. In either case, our study offers little support for the notion that, in the domain of altruistic choices, the individual must spend cognitive resources to override the intuitive impulse when the person wants to take a choice favored by the deliberative system.