Witness for resolution: post-conflict quadratic affiliation in semi-free ranging pigs

Area of Science:

• Ethology
• Animal Behavior
• Social Cognition

Background:

• Post-conflict social interactions in mammals include reconciliation, triadic contacts, and bystander (quadratic) contacts.
• Quadratic contacts, involving affiliation between individuals not directly involved in a conflict, have been understudied.
• Understanding quadratic contacts may offer insights into complex cognitive abilities in social species.

Purpose of the Study:

• To investigate the occurrence and function of quadratic affiliation in semi-free ranging pigs (Sus scrofa).
• To determine if quadratic affiliation serves to regulate bystander anxiety.
• To explore the influence of kinship and direct conflict resolution on quadratic affiliation.

Main Methods:

• Behavioral data collected from 104 adult pigs over 43 hours of video recordings.
• Affiliative and anxiety behaviors of bystanders analyzed under post-conflict (PC) and matched-control (MC) conditions.
• Kinship data utilized to assess the role of relatedness in quadratic affiliation.

Main Results:

• Pigs exhibited significantly more quadratic affiliation in PC conditions compared to MC.
• Quadratic affiliation was followed by a reduction in anxiety behaviors in the interacting bystanders.
• Quadratic affiliation was highest between close kin and decreased when reconciliation or triadic contacts occurred.

Conclusions:

• Quadratic affiliation in pigs appears to serve an intrinsic anxiety-regulation function for bystanders.
• The effectiveness and occurrence of quadratic affiliation are modulated by kinship and direct conflict resolution.
• Pigs demonstrate sensitivity to the negative experiences of others, potentially indicating social appraisal abilities.