Psychology needs more replication. For the field to be a cumulative and robust science, we need to be able to verify that effects hold up in new samples. Particularly in the case of seminal findings that inspired long lines of follow-up research, it is of interest to assess if the original result is reliable.

 

In the current study, Leong and colleagues (2025) propose a high-powered direct replication of a seminal experiment by Rozin et al. (1997). In an online sample, the authors investigate attitudinal differences between moral vegetarians and health vegetarians, to study the consequences of moralization. The authors stay close to the original design, in order to allow for a clear conclusion on whether the findings of the original study has been successfully replicated or not. This study is part of a large collaborative effort to replicate seminal findings in in social psychology and decision-making.

 

This replication study has the potential to 1) increase our understanding of moralization, especially in the context of vegetarianism, and 2) allow for a systematic assessment of replicability in the social sciences.

 

The Stage 1 manuscript was evaluated over two rounds of in-depth review. Based on detailed responses to the reviewers' comments, the recommender judged that the manuscript met the Stage 1 criteria and therefore awarded in-principle acceptance (IPA).

 

URL to the preregistered Stage 1 protocol: https://osf.io/6pyhf
 
Level of bias control achieved: Level 6. No part of the data or evidence that will be used to answer the research question yet exists and no part will be generated until after IPA.
 
List of eligible PCI RR-friendly journals:

 

• Collabra: Psychology
• International Review of Social Psychology
• Meta-Psychology
• Peer Community Journal
• PeerJ
• Royal Society Open Science
• Social Psychological Bulletin
• Studia Psychologica
• Swiss Psychology Open

 

 

1. Leong, U., Chan, E. H. L., Yau, W. T., Ng, W. Y., Chim, T. W., Yeung, W., Tam, K. Y. Y., & Feldman, G. (2025). Revisiting the morality of vegetarianism and veganism: Replication Registered Report of Rozin et al. (1997). In principle acceptance of Version 3 by Peer Community in Registered Reports. https://osf.io/6pyhf

 

2. Rozin, P., Markwith, M., & Stoess, C. (1997). Moralization and becoming a vegetarian: The transformation of preferences into values and the recruitment of disgust. Psychological Science, 8, 67-73. https://doi.org/10.1111/j.1467-9280.1997.tb00685.x