Reciprocity is an extremely powerful tool in compliance, but why? Most people assume that it is because, as humans, we do not like to be met with social disapproval (Wedekind & Milinski, 2000), but is this the only reason? How much of the compliance is due to an internal struggle?
Whatley, Webster, Smith and Rhodes (1999) conducted an experiment on whether compliance would change if the act was private or public. The participant met a confederate posing as another participant whilst waiting to take part in a study. They then got called in to take part in what they thought was the study (rating pieces of art), that had a 3 minute break half way through. During the break, half of the participants were given a packet of M&M’s by the confederate (favour condition) while the other half were given nothing (non-favour condition). When participants thought they had completed the study, the experimenter returned with a donation form for a sponsored run saying that the confederate had given it to them to pass on to the participant. Half of the subjects were given a form that asked for their name and address (the public condition) while the other half were given an anonymous form on which to put their pledge (private condition).
The results replicated previous findings that if you receive an unsolicited favour you are more likely to comply with subsequent requests from that person. The main finding of this study is that this appears to be true regardless of whether the compliance is public or private.
The study suggests that it is not only social motivation that makes reciprocity such a powerful compliance technique; internal motivations also play a part. However you can see from the graph the public condition were on average more likely to pledge, which was expected.
Wedekind, C., & Milinski, M. (2000). Cooperation through image scoring in humans. Science, 288(5467), 850-852.
Whatley, M. A., Webster, J. M., Smith, R. H., & Rhodes, A. (1999). The effect of a favour on public and private compliance: How internalized is the norm of reciprocity? Basic and Applied Social Psychology, 21(3), 251-259.