Boose Klaree, White Frances
Department of Anthropology, 1218 University of Oregon, Eugene, OR, 97403, USA.
Primates. 2017 Oct;58(4):493-504. doi: 10.1007/s10329-017-0616-9. Epub 2017 Jun 13.
The immatures of many primate species frequently pester adult group members with aggressive behaviors referred to as a type of harassment. Although these behaviors are characteristic of immatures as they develop from infancy through adolescence, there have been few studies that specifically address the adaptive significance of harassment. Two functional hypotheses have been generated from observations of the behavior in chimpanzees. The Exploratory Aggression hypothesis describes harassment as a mechanism used by immatures to learn about the parameters of aggression and dominance behavior and to acquire information about novel, complex, or unpredictable relationships. The Rank Improvement hypothesis describes harassment as a mechanism of dominance acquisition used by immatures to outrank adults. This study investigated harassment of adults by immatures in a group of bonobos housed at the Columbus Zoo and compared the results to the predictions outlined by the Exploratory Aggression and Rank Improvement hypotheses. Although all immature bonobos in this group harassed adults, adolescents performed the behavior more frequently than did infants or juveniles and low-ranking adults were targeted more frequently than high-ranking. Targets responded more with agonistic behaviors than with neutral behaviors and the amount of harassment an individual received was significantly correlated with the amount of agonistic responses given. Furthermore, bouts of harassment were found to continue significantly more frequently when responses were agonistic than when they were neutral. Adolescents elicited mostly agonistic responses from targets whereas infants and juveniles received mostly neutral responses. These results support predictions from each hypothesis where harassment functions both as a mechanism of social exploration and as a tool to establish dominance rank.
许多灵长类物种的未成年个体经常会用一种被称为骚扰的攻击性行为来纠缠成年群体成员。尽管这些行为是未成年个体从婴儿期到青春期发育过程中的特征，但很少有研究专门探讨骚扰行为的适应性意义。基于对黑猩猩行为的观察，产生了两种功能性假设。探索性攻击假设将骚扰描述为未成年个体用来了解攻击和支配行为参数以及获取有关新奇、复杂或不可预测关系信息的一种机制。等级提升假设将骚扰描述为未成年个体用来超越成年个体以获取支配地位的一种机制。本研究调查了哥伦布动物园一群倭黑猩猩中未成年个体对成年个体的骚扰行为，并将结果与探索性攻击假设和等级提升假设所概述的预测进行了比较。尽管这群倭黑猩猩中的所有未成年个体都骚扰成年个体，但青少年比婴儿或幼年个体更频繁地表现出这种行为，并且低等级成年个体比高等级成年个体更频繁地成为目标。目标个体对骚扰行为的反应更多是对抗性行为而非中性行为，并且个体受到的骚扰量与所给出的对抗性反应量显著相关。此外，当目标个体的反应是对抗性的时候，骚扰行为的持续时间明显比反应是中性的时候更频繁。青少年引发的大多是目标个体的对抗性反应，而婴儿和幼年个体收到的大多是中性反应。这些结果支持了每个假设的预测，即骚扰行为既作为一种社会探索机制，又作为一种确立支配等级的工具发挥作用。
