Partial support from a nonreplication: Comment on Roma, Silberberg, Ruggiero, and Suomi (2006)

A purported replication by P. G. Roma, A. Silberberg, A. M. Ruggiero, and S. J. Suomi (2006) of the authors' previous study (S. F. Brosnan & F. B. M. de Waal, 2003) claims to contradict their finding that capuchin monkeys (Cebus apella) refuse to exchange with an experimenter if their partner receives a superior reward. Roma et al. used no exchange task, however, or any other task. Roma et al. offered frustration as explanation of their findings, yet failed to statistically prove that the effect of frustration is stronger than that of inequity. They also misrepresented the dependent measure of the authors' study. Reanalysis of the authors' own data indicated no role of frustration, that is, no effect of previous experience with a superior reward. The authors conclude that Roma et al.'s study is not a replication and does not disprove the authors' findings.