In social mammals, post-conflict resolution can involve the reunion of former opponents (reconciliation), spontaneous/solicited post-conflict affiliation of a third party with either opponent (triadic contacts), and affiliation between other individuals (hereafter bystanders; quadratic contacts). Quadratic contacts – possibly informing complex cognitive abilities - have been neglected in post-conflict studies. We investigated quadratic affiliation in semi-free ranging pigs Sus scrofa, housed at the ethical farm Parva-Domus (Cavagnolo, Italy). Kinship was known. We collected behavioral data on adult pigs (n = 104) via video recordings (43-hrs) followed by video analyses. Affiliative and anxiety behaviours between bystanders were collected under Post-Conflict (PC; following a conflict between non-bystanders) and Matched-Control (MC; no conflict) conditions. Quadratic affiliation was present in pigs, as bystanders affiliated more in PC than MC, and that such affiliation was followed by a decrease in the anxiety behaviours of both the interacting bystanders. Thus, quadratic contacts may be mainly aimed at reducing one's own anxiety (intrinsic regulation). Quadratic affiliation was highest between closely related bystanders, which suggests that such affiliation may be most effective when close kin is involved. Quadratic affiliation was lowest after reconciliation and spontaneous triadic contacts. This suggests that direct peacemaking between opponents and spontaneous triadic contacts with close kin may most likely replace quadratic affiliation. Hence, pigs can be affected by the negative events that affect other pigs – but not themselves - and their response may be modulated by social factors. Such non-random quadratic affiliation may point toward the presence of elements of social appraisal abilities in pigs.

中文翻译：

---

解决方案的见证：半自由放养猪的冲突后二次从属关系

在社会哺乳动物中，冲突后的解决可能涉及前对手的团聚（和解），第三方与任一对手的自发/受邀的冲突后联系（三元接触），以及其他个体之间的联系（以下称为旁观者；二次接触） . 二次接触——可能影响复杂的认知能力——在冲突后研究中被忽视了。我们调查了饲养在道德农场 Parva-Domus（意大利卡瓦尼奥洛）的半自由放养猪 Sus scrofa 的二次从属关系。亲属关系是众所周知的。我们通过视频记录（43 小时）收集成年猪 (n = 104) 的行为数据，然后进行视频分析。旁观者之间的从属关系和焦虑行为是在冲突后（PC；非旁观者之间的冲突之后）和匹配控制（MC；无冲突）条件。二次从属关系存在于猪中，因为旁观者更倾向于 PC 而不是 MC，并且这种从属关系之后交互的旁观者的焦虑行为都会减少。因此，二次接触可能主要是为了减少自己的焦虑（内在调节）。密切相关的旁观者之间的二次从属关系最高，这表明当涉及近亲时，这种从属关系可能最有效。在和解和自发的三方接触后，二次方关系最低。这表明，对手之间的直接调停和与近亲的自发三方接触很可能会取代二次方关系。因此，猪可能会受到影响其他猪的负面事件的影响——但不会影响它们自己——它们的反应可能会受到社会因素的调节。这种非随机二次从属关系可能指向猪的社会评价能力要素的存在。