Trust is a fundamental element for the well-functioning of our society. By achieving large levels of trust, societies can reduce monitoring costs (e.g., contract supervision, conflict resolution) and increase investments in more profitable but socially riskier projects. Trust serves as a way to foster cooperation among individuals and can benefit the entire social group.

 

As a result, numerous researchers have sought to explore the biological foundations of trust. In particular, several research teams have tried to explore the role of oxytocin in modulating prosocial behaviors. However, previous research findings obtained mixed findings, and several methodological issues, such as low statistical power, have hindered the development of a definite view on the matter.

 

In the current study, Kroll et al. (2023) seek to replicate the seminal study of Kosfeld et al. (2005). Kosfeld and co-authors originally found that the intranasal administration of oxytocin can significantly increase trust among individuals. However, recent replication evidence shows no general effect of oxytocin on pro-social behaviors or suggests that the effect might be heterogeneous among social groups (Declerck et al., 2020). The objective of the current study of Kroll et al. (2023) is twofold. First, the authors propose to replicate the original study of Kosfeld et al. (2005) and to investigate whether the lack of replication can be due to an overall effect that is smaller than the original findings suggest. Second, the authors propose to replicate recent but exploratory results on the heterogeneous effect of oxytocin on pro-social choices. 

 

The Stage 1 manuscript was evaluated over one round 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).

 

 

Level of bias control achieved: Level 4. At least some of the data/evidence that will be used to answer the research question already exists AND is accessible in principle to the authors (e.g. residing in a public database or with a colleague) BUT the authors certify that they have not yet accessed any part of that data/evidence.

 

 

 

 

1. Declerck, C. H., Boone, C., Pauwels, L., Vogt, B., & Fehr, E. (2020). A registered replication study on oxytocin and trust. Nature Human Behaviour, 4(6), 646–655. https://doi.org/10.1038/s41562-020-0878-x

 

2. Kosfeld, M., Heinrichs, M., Zak, P. J., Fischbacher, U., & Fehr, E. (2005). Oxytocin increases trust in humans. Nature, 435(7042), 673–676. https://doi.org/10.1038/nature03701

 

3. Kroll, C. F., Schruers, K., Viechtbauer, W., Vingerhoets, C., Seidel, L., Riedl, A. & Hernaus, D. (2023). Oxytocin, individual differences, and trust game behavior: a registered large-scale replication, in principle acceptance of Version 2 by Peer Community in Registered Reports. https://osf.io/h5gdp