The impact of informal social networks and irrationality on small groups’ task performances: an experimental study

Social network empirical studies, focused on small groups, usually aim to identify structural properties that allow greater performances in relation to specific tasks. In recent decades, behavioral economics has shown that individuals may be, in a specific sense, irrational and there are certain circumstances in which they perform irrationally in a predictable way; these circumstances constitute what I call “irrationality inducements”. This phenomenon, in different social structured groups, is still largely unexplored; therefore, I aim to answer the following research question:  Which is the impact of informal social networks and irrationality on small groups’ task performances? In order to answer this question, I chose to run several laboratory experiments on 4-person small groups. They were constructed by the researcher on the basis of existing trust relations among 300 individuals who have known each other for some time. One type of group defined by the researcher was centralized (a sociometric star): all trust relations involved a single central person. A second type of group was a sociometric clique: everyone trusted every one. A third type of group was an empty graph: no trust ties within the group at all. The laboratory experiments allowed us to input irrationality inducements such as “anchor effect”, “asymmetric dominance effect” and “different level of incentives” on these differently structured groups. In each experiment I have been able to measure readily performances at the group level. Like the Bavelas-Leavitt experiments of the 1950s, I was able to measure several aspects of each group’s performance. A number of interesting results emerged from this study, including the marked tendency for stars to be more suscettible to anchoring bias in estimation tasks and cliques to be more suscettible to the irrational detrimetral effect of incentives in decision making tasks. We can say that irrationality has significant impact on group performance as predicted by behavioral economics. However, this result seems to be driven interestingly by the informal structure and the assigned task..