Normative interventions, emergent cognition and decision rationality in ad hoc and established groups

Purpose – As normative interventions (NIs) have been claimed to be effective in improving decision quality in groups, the aim of the paper is to address the effectiveness of NIs in ad hoc and established groups across several task domains. Design/methodology/approach – Three experimental studies were conducted to test the effects of NIs on collective cognition, group rationality, and decision quality. Findings – The first experimental study (58 groups) compared the effects of NIs on the emergence of group level cognitive structures. The results show that NIs lead to higher group cognitive complexity in established rather than in ad hoc groups. The second study tests the effects of NIs on group rationality (as emergent group competence) in a sample of 40 established groups and shows that NIs have synergic effects and foster group rationality. In the third study the insights of the first two studies are extended to a more realistic decision task performed by groups of managers. The results of the last study show that decision quality is higher in groups that received NIs as compared to groups that did not receive NIs. Research limitations/implications – The results contribute to the group cognition literature by showing the synergic effects of NIs. Practical implications – The results show that NIs are simple and effective ways of improving information processing and decision quality in established decision‐making groups. Social implications – NIs help in achieving better decisions throughout society. Originality/value – The paper is the first comprehensive test of the impact of NIs on group information processing across several cognitive tasks and the first to explore group rationality as an emergent group‐level competence.