Investigating Variation in Replicability: A “Many Labs” Replication Project

Richard Klein, Kate A. Ratliff, Michelangelo Vianello, Reginald B. Adams, Štěpán Bahník, Michael H. Bernstein, Konrad Bocian, Mark Brandt, Beach Smith Brooks, Claudia Chloe Brumbaugh,

2022 · 118 citations · 0 references

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TL;DR

Replication is a core principle of science, yet direct replications are uncommon in psychology. The study examined how replicability varies across thirteen classic and contemporary effects using 36 independent samples of 6,344 participants. The authors compared whether factors such as lab versus online settings or U.S. versus international samples predicted effect sizes.

Abstract

Although replication is a central tenet of science, direct replications are rare in psychology. This research tested variation in the replicability of thirteen classic and contemporary effects across 36 independent samples totaling 6,344 participants. In the aggregate, ten effects replicated consistently. One effect – imagined contact reducing prejudice – showed weak support for replicability. And two effects – flag priming influencing conservatism and currency priming influencing system justification – did not replicate. We compared whether the conditions such as lab versus online or U.S. versus international sample predicted effect magnitudes. By and large they did not. The results of this small sample of effects suggest that replicability is more dependent on the effect itself than on the sample and setting used to investigate the effect.