Demonstrating the limitations of the one-at-a-time approach, crowd initiatives reveal the surprisingly powerful role of analytic and design choices in shaping scientific results. At the same time, cross-cultural variability in effects is far below the levels initially expected. This highlights the value of “medium” science, leveraging diverse stimulus sets and extensive robustness checks to achieve integrative tests of competing theories.

By organizing crowds of scientists to independently tackle the same research questions, we can collectively overcome the generalizability crisis. Strategies to draw inferences from a heterogeneous set of research approaches include aggregation, for instance, meta-analyzing the effect sizes obtained by different investigators, and parsing, attempting to identify theoretically meaningful moderators that explain the variability in results.

Contradicting our earlier claims of American moral exceptionalism, recent self-replication evidence from our laboratory indicates that implicit puritanism characterizes the judgments of people across cultures. Implicit cultural evolution may lag behind explicit change, such that differences between traditional and non-traditional cultures are greater at a deliberative than an intuitive level. Not too deep down, perhaps we are all implicit puritans.

Critical aspects of the “rationality of rationalizations” thesis are open empirical questions. These include the frequency with which past behavior determines attitudes (as opposed to attitudes causing future behaviors), the extent to which post hoc justifications take on a life of their own and shape future actions, and whether rationalizers experience benefits in well-being, social influence, performance, or other desirable outcomes.