Selection for Collective Aggressiveness Favors Social Susceptibility in Social Spiders
Authors: James L L Lichtenstein
Noa Pinter-Wollman
Colin M Wright
Gregory T Chism
Brendan L McEwen
Jonathan N Pruitt
Ambika Kamath
Journal: Current Biology (2018)
Discipline: BIOLOGY & BIOCHEMISTRY
Keywords: animal leadership; behavioral syndrome; personality; social evolution; spiders
Affiliations: Department of Ecology, Evolution and Marne Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA. Electronic address: ., Department of Ecology, Evolution and Marne Biology, University of California, Santa Barbara, Santa Barbara, CA 93106, USA., Graduate Interdisciplinary Program in Entomology and Insect Science, University of Arizona, Tucson, AZ 85721, USA., Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA 37906, USA., Department of Ecology and Evolutionary Biology, University of California, Los Angeles, Los Angeles, CA 90095, USA.

Abstract:  Particularly socially influential individuals are present in many groups [1-8], but it is unclear whether their emergence is determined by their social influence versus the social susceptibility of others [9]. The social spider Stegodyphus dumicola shows regional variation in apparent leader-follower dynamics. We use this variation to evaluate the relative contributions of leader social influence versus follower social susceptibility in driving this social order. Using chimeric colonies that combine potential leaders and followers, we discover that leader-follower dynamics emerge from the site-specific social susceptibility of followers. We further show that the presence of leaders increases colony survival in environments where leader-follower dynamics occur. Thus, leadership is driven by the "social susceptibility" of the population majority, rather than the social influence of key group members. 

Retracted: No

PubPeer comments:
 I have been examining the raw data deposited at the dryad digital repository . There are a few odd patterns in the data, but one pattern in particular is extremely interesting. It is a little complicated, so please bear with me. In the u201cChimera Datau201d tab, the data is originally sorted by columns u201cTreatmentu201d then u201cSite Combou201d and then the u201cBoldness of Keystoneu201d column is ordered haphazardly in a roughly increasing order. Below is a screenshot of the raw data for reference: ![file] Now here is where it gets interesting. If you re-sort this data by just u201cTreatmentu201d and then u201cBoldness of Keystoneu201d (ignoring u201cSite Combou201d), a pattern emerges between two of the treatments. Specifically, the u201cBold Mimosarum_Shy Aridu201d and u201cBold Wet_Shy Aridu201d treatments have the u201cBoldness of Keystoneu201d value increase in parallel over large series of data. In general, these data have the following relationship: the u201cBoldness of Keystoneu201d of the u201cBold Wet_Shy Aridu201d treatment is equal to the u201cBoldness of Keystoneu201d of the u201cBold Mimosarum_Shy Aridu201d treatment plus two. I am including screenshots of this pattern below with the two treatments shown next to each other. Values that directly align to the +2 relationship are highlighted in yellow. Values that show the +2 relationship but are slightly offset are highlighted in orange. Based on my understanding of the methods of this paper, I find myself unable to understand how this pattern has emerged. The u201cBold Mimosarum_Shy Aridu201d treatment measured the boldness of individuals of the species *Stegodyphus mimosarum*. In contrast, the u201cBold Wet_Shy Aridu201d treatment measured the boldness of individuals of the species *S. dumicola*. Each boldness value should represent the measurement of a single spider in an independent trial. As far as I can understand, these trials should be totally independent, even if they were conducted on the same species. Could the authors please explain? ![file] rest of the data continued below: ![file] , 
 Thank you for your quarries. We will be working through formal channels on an official response to this matter. Noa Pinter-Wollman , 
  This paper and the experiments within have shown that the leader-follower dynamic is dependent not on the strength of a bold and influential leader, but on the willingness of the shy followers to be influenced. While social spiders differ from other organisms in many respects, it is interesting to think what this could mean for the rest of the animal kingdom. We tend to think of the strong and charismatic leader of a group as the most important part of the equation, but it may be that their influence only matters because the followers are u201clookingu201d for some direction in their own lives.  https: ecologyforthemasses.com 2018 08 02 fortune-favors-the-bold-spider ,