Collective Intelligence

People rarely make decisions in isolation. Instead, they tap into the information and knowledge provided by their social environment (i.e., other individuals) to make better decisions. Under certain conditions, though, the social environment can also pose a threat—for example, when crowds stampede or political opinions polarize. The ability to successfully navigate the social environment is a key competence for adaptive decision making in an uncertain world. 

Use of Social Information

In our research, we try to understand how individuals integrate information provided by others. This requires an understanding of how and when people search for social information (e.g., whom they trust), how they integrate conflicting personal and social information, how information flows through populations, and how these processes are shaped by the structure of social interactions and individual characteristics (e.g., search strategy, confidence, and expertise). To answer these questions, we combine empirical studies observing real-world behavior with theoretical simulations that scale up the observed behaviors to larger populations. In addition, we use cognitive modeling techniques to better understand how people integrate personal and social information, and how groups arrive at joint decisions.

Wisdom of Crowds

Another powerful method for boosting decision accuracy is to combine the independent decisions of different people. This “wisdom of the crowd” approach is often more accurate than the judgements of single individuals. We examine when and why different ways of aggregating information lead to improved collective performance, combining empirical research methods (e.g., large online studies, lab studies, virtual reality, and human crowds) with advanced theoretical modeling. We also apply the insights gained from this research to real-world domains with high stakes, including medical diagnostics, human crowds (e.g., during emergency evacuations), and geopolitical forecasting, with the aim of enabling decision makers to make better decisions by joining forces.


  • El Zein, M., Bahrami, B., & Hertwig, R. (2019). Shared responsibility in collective decisions. Nature Human Behaviour3, 554-559.
  • Herzog, S. M., Litvinova, A., Yahosseini, K. S., Tump, A. N., & Kurvers, R. H. J. M. (2019). The ecological rationality of the wisdom of crowds. In R. Hertwig, T. J. Pleskac, T. Pachur, & the Center for Adaptive Rationality, Taming Uncertainty. Cambridge, MA: MIT Press.
  • Kurvers R. H. J. M., Herzog, S. M., Hertwig, R., Krause, J., Carney, P. A., Bogart, A., … Wolf, M. (2016). Boosting medical diagnostics by pooling independent judgments. Proceedings of the National Academy of Sciences,113, 8777–8782.
  • Moussaïd, M., Herzog, S. M., Kämmer, J. E., & Hertwig, R. (2017). Reach and speed of judgment propagation in the laboratory. Proceedings of the National Academy of Sciences114, 4117–4122.
  • Tump, A. N., Pleskac, T. J., & Kurvers, R. H. J. M. (2020). Wise or mad crowds? The cognitive mechanisms underlying information cascades. Science Advances6(29), Article eabb0266.
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