Diversity promotes abstraction and cognitive flexibility in collective problem solving

Social interaction plays an important role in many contexts of human reasoning and problem solving, and groups are often found to outperform individuals. We suggest that this benefit is associated with the dialogical sharing and integration of diverse perspectives and strategies. Here, we investigated whether diversity in prior experience affects groups’ problem representations and performance. In a game-like experiment, participants categorized aliens based on combinations of their features. Whenever a specific feature combination was learned, the rule changed and a new feature combination had to be learned. However, unbeknown to participants, rule changes were governed by an abstract meta-rule and awareness of this provided an advantage when rules changed. We compared categorization performance between individuals, groups composed of members trained on the same rule, and groups composed of members trained on different rules before entering the collaborative test phase. Following preregistered predictions, groups with diverse task experience outperformed groups with similar task experience, which in turn outperformed individuals. These findings were unaffected diversity in personality (Big Five) and motivational factors, suggesting that diversity in experience plays the key role. We conclude that cognitive diversity impact problem solving by stimulating processes of abstraction and flexibility at the level of the group.