Oxytocin Homogenizes Horse Group Organization

Authors

• James Brooks
• Tamao Maeda
• Monamie Ringhofer
• Shinya Yamamoto

Language

English

Publication Date

7-19-2024

Journal

iScience

DOI

10.1016/j.isci.2024.110356

PMID

PMC11277748

PMCID

39071893

PubMedCentral® Posted Date

6-24-2024

PubMedCentral® Full Text Version

Post-print

Abstract

The oxytocinergic system has been suggested to make up an important part of the endocrine basis of group cohesion. However, controlled studies in open-group settings have not been performed. We here investigated the impact of exogenous intranasal oxytocin on the group-level social organization of 5 groups of horses (N = 58; 12 mares and 46 geldings) through GPS tracking and social network analysis. We find oxytocin flattened social differentiation across levels. Most strikingly, oxytocin did not simply reinforce existing bonds but selectively shifted social preferences toward homogenization – individuals and pairs who otherwise rarely associated spent more time close together, while individuals and pairs with the highest baseline association instead spent more time further apart. This resulted in a more distributed structure and lower clustering coefficient at the network level. These effects reinforce and extend oxytocin’s role in collective behavior, social organization, and the evolution of group-based sociality across taxa.

Keywords

Wildlife physiology, Zoology, Evolutionary biology

Published Open-Access

yes

Recommended Citation

Brooks, James; Maeda, Tamao; Ringhofer, Monamie; et al., "Oxytocin Homogenizes Horse Group Organization" (2024). Faculty, Staff and Students Publications. 8714.
https://digitalcommons.library.tmc.edu/baylor_docs/8714