Fragmented social networks promote complex behavioural contagions over infectious disease spread
- 1Institute of Ecology and Evolution, School of Biological Sciences, The University of Edinburgh, Edinburgh, EH9 3FL, UK
- 2Department of Biology, Georgetown University, Washington D.C. 20057, USA
Abstract
Group living and social interactions among animals provide key benefits, such as the exchange of beneficial social information and novel behaviours, but also often pose the risk of spreading costly infectious diseases, presenting a social trade-off. While both behaviours and infections spread across social networks, they typically have distinct mechanisms of transmission. Here, we model social behaviour spread as a complex contagion governed by a conformist learning rule, while pathogen transmission follows a simple contagion mechanism. Building on theoretical foundations, our study applies computational models to examine how (sub)group structure (modularity) influences the spread of these contagions across diverse animal social structures sourced from the Animal Social Network Repository. Our findings reveal that high modularity and (sub)group structure slow simple contagion spread, whereas complex contagions are less impeded by this fragmentation but with a relatively small effect size compared with theoretical predictions. Consequently, our results suggest that social networks divided into small groups or subgroups can help balance the competing pressures of exploiting beneficial social information and avoiding infectious disease in real-world networks.
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BibTeX
@article{wijayatilake2026fragmented,
title = {{Fragmented social networks promote complex behavioural contagions over infectious disease spread}},
author = {Nitara Wijayatilake and Shweta Bansal and Amy B. Pedersen and Matthew J. Silk},
journal = {Proceedings of the Royal Society B: Biological Sciences},
year = {2026},
month = oct,
doi = {10.1098/rspb.2026.1424},
url = {https://doi.org/10.1098/rspb.2026.1424},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Fragmented social networks promote complex behavioural contagions over infectious disease spread
AU - Nitara Wijayatilake
AU - Shweta Bansal
AU - Amy B. Pedersen
AU - Matthew J. Silk
PY - 2026
DA - 2026/10/21
JO - Proceedings of the Royal Society B: Biological Sciences
DO - 10.1098/rspb.2026.1424
UR - https://doi.org/10.1098/rspb.2026.1424
AB - Group living and social interactions among animals provide key benefits, such as the exchange of beneficial social information and novel behaviours, but also often pose the risk of spreading costly infectious diseases, presenting a social trade-off. While both behaviours and infections spread across social networks, they typically have distinct mechanisms of transmission. Here, we model social behaviour spread as a complex contagion governed by a conformist learning rule, while pathogen transmission follows a simple contagion mechanism. Building on theoretical foundations, our study applies computational models to examine how (sub)group structure (modularity) influences the spread of these contagions across diverse animal social structures sourced from the Animal Social Network Repository. Our findings reveal that high modularity and (sub)group structure slow simple contagion spread, whereas complex contagions are less impeded by this fragmentation but with a relatively small effect size compared with theoretical predictions. Consequently, our results suggest that social networks divided into small groups or subgroups can help balance the competing pressures of exploiting beneficial social information and avoiding infectious disease in real-world networks.
SN - 0962-8452
SN - 1471-2954
ER -