Public evening lecture by Professor Jens Krause, PhD (Leibniz Institute of Freshwater Ecology and Inland Fisheries, part of the Berlin Research Alliance e.V.)

Studies on collective cognition provide numerous examples of how the efficient dissemination of information within groups leads to benefits as group size increases. However, little is known about whether groups also amplify maladaptive information, such as false alarms, and whether such costs reduce potential benefits. In this study, we investigated wild fish shoals that react collectively with escape dives when attacked by birds. We analysed the collective response to bird attacks and to similar but harmless fly-bys as a function of shoal size. Larger shoals became increasingly better at recognising predator attacks, whilst their response to harmless fly-bys remained constant. Furthermore, decision-making time decreased as shoal size increased. Larger shoals were thus able to simultaneously overcome two key trade-offs typical of individual decision-making: the trade-off between false and true alarms, and the trade-off between speed and accuracy.
I will place these findings in the context of examples of human collective cognition dealing with similar problems and attempt to derive a general definition of collective cognition from them. At the end of my talk, I will explain how our work on collective cognition forms part of a broader research programme on the ‘Science of Intelligence’, which is being developed within our Cluster of Excellence of the same name in Berlin (https://www.scienceofintelligence.de/).

Moderators: Denise Becker and Jule Meyer B.Sc.