Has the evidence for moral licensing been inflated by publication bias?

Abstract

Moral licensing describes the phenomenon that displaying moral behavior can lead to subsequent immoral behavior. This is usually explained by the idea that an initial moral act affirms the moral self-image and hence licenses subsequent immoral acts. Previous meta-analyses on moral licensing indicate significant overall effects of d> .30. However, several large replication studies have either not found the effect or reported a substantially smaller effect size. The present article investigated whether this can be attributed to publication bias. Datasets from two previous meta-analyses on moral licensing were compared and when necessary modified. The larger dataset was used for the present analyses. Using PET-PEESE and a three-parameter-selection-model (3-PSM), we found some evidence for publication bias. The adjusted effect sizes were reduced to d= -0.05, p= .64 and d= 0.18, p= .002, respectively. While the first estimate could be an underestimation, we also found indications that the second estimate might exaggerate the true effect size. It is concluded that both the evidence for and the size of moral licensing effects has likely been inflated by publication bias. Furthermore, our findings indicate that culture moderates the moral licensing effect. Recommendations for future meta-analytic and empirical work are given. Subsequent studies on moral licensing should be adequately powered and ideally pre-registered.