The replication crisis in (health) psychology: reflections and solutions

Abstract

Aims: The overarching aim of the symposium is to reflect on the replication crisis in psychology and the implications this has for health psychology, as well as to provide solutions aimed at getting out of this crisis. We aim to shed more light on (1) what we can learn from multilab replications; (2) how the replication crisis is related to the distribution of effect sizes and the role of failures to randomize. Subsequently, we focus on (3) what this means for reproducibility of intervention research within health psychology and (4) why targeting next generations is an important part of the solution to the replication crisis. Rationale: The results of the efforts by the Open Science Collaboration to replicate 100 experiments reported in papers in three high-ranking psychology journals led to a lot of debate, both within science and popular press. However, limited attention has been paid to this issue on previous EHPS conferences, while this is highly relevant for health psychology, especially with regard to intervention research. Moreover, this is relevant for our undergraduate and postgraduate curricula. Summary: Martin Hagger presents lessons learned from a multilab replication of the ego-depletion effect and what implications this has for matters arising from the replication crisis within health psychology. Gjalt-Jorn Peters explains how replicability is determined by the likelihood that randomisation successfully generates equivalent groups and the accuracy of effect size estimation, and shows how both are determined by sample size. Matti Heino elaborates on the relevance of the recent reproducibility movement with regard to large-scale intervention research. Rik Crutzen presents part of the solution by means of targeting the next generations by updating our curricula. Marie Johnston, finally, reflects on these presentations and leads the discussion that follow from them.