Sutter, Matthias Max Planck Institute for Research on Collective Goods, Max Planck Society;
https://doi.org/10.1073/pnas.1320451111 (Any fulltext)
Lergetporer, P., Angerer, S., Glätzle-Rützler, D., & Sutter, M. (2014). Third-party punishment increases cooperation in children through (misaligned) expectations and conditional cooperation. PNAS - Proceedings of the National Academy of Sciences, 11, 6916-6921.