Keystone individuals

In some societies, one or few individuals have a disproportionate impact on the collective behavior of the groups. Examples include leaders and tutors and a general term refers to these as ‘keystone individuals’. In the social spider Stegodyphus dumicola, keystone individuals are bolder than all other group members and they expedite collective prey attack. Their influence over others is long lasting and persists even after they are no longer in the group [1]. Keystone individuals can ‘mislead’ their group if they acquire wrong information [2] and their influence on other group members can determine disease dynamics within the colony. [3]  We examine how interactions among individuals determine the impact of keystone individuals on the behavior of other group members.

1. Pruitt JN & Pinter-Wollman N. 2015. The legacy effects of keystone individuals on collective behavior scale to how long they remain within a group. Proc. Roy. Soc. B. 282:20151766.

2. Pruitt J.N., Wright C.M., Keiser C.N., DeMarco A., Grobis M.M., & Pinter-Wollman N. 2016. The Achilles heel hypothesis: misinformed keystone individuals impair collective learning and reduce group success. Proceedings of the Royal Society B. 283: 20152888.

3. Keiser C.N., Pinter-Wollman N., Augustine D., Ziemba M., Hao L., Lawrence J., & Pruitt J.N. 2016. Individual differences in boldness influence patterns of social interactions and the transmission of cuticular bacteria among group-mates. Proceedings of the Royal Society B. 283: 20160457

S. dumicola adult female

S. dumicola

S. dumicola females with spiderlings on the web of their nest


Juvenile S. dumicola painted for unique identification