Natarajan Deepa, Caramaschi Doretta
Department of Behavioral Physiology, Biological Center, University of Groningen Haren, Netherlands.
Front Behav Neurosci. 2010 Apr 5;4:9. doi: 10.3389/fnbeh.2010.00009. eCollection 2010.
Violence has been observed in humans and animals alike, indicating its evolutionary/biological significance. However, violence in animals has often been confounded with functional forms of aggressive behavior. Currently, violence in animals is identified primarily as either a quantitative behavior (an escalated, pathological and abnormal form of aggression characterized primarily by short attack latencies, and prolonged and frequent harm-oriented conflict behaviors) or a qualitative one (characterized by attack bites aimed at vulnerable parts of the opponent's body and context independent attacks regardless of the environment or the sex and type of the opponent). Identification of an operational definition for violence thus not only helps in understanding its potential differences from adaptive forms of aggression but also in the selection of appropriate animal models for both. We address this issue theoretically by drawing parallels from research on aggression and appeasement in humans and other animals. We also provide empirical evidences for violence in mice selected for high aggression by comparing our findings with other currently available potentially violent rodent models. The following violence-specific features namely (1) Display of low levels of pre-escalatory/ritualistic behaviors. (2) Immediate and escalated offense durations with low withdrawal rates despite the opponent's submissive supine and crouching/defeat postures. (3) Context independent indiscriminate attacks aimed at familiar/unfamiliar females, anaesthetized males and opponents and in neutral environments. (4) Orientation of attack-bites toward vulnerable body parts of the opponent resulting in severe wounding. (5) Low prefrontal serotonin (5-HT) levels upon repeated aggression. (6) Low basal heart rates and hyporesponsive hypothalamus-pituitary-adrenocortical (HPA) axis were identified uniquely in the short attack latency (SAL) mice suggesting a qualitative difference between violence and adaptive aggression in animals.
在人类和动物中均观察到了暴力行为，这表明其具有进化/生物学意义。然而，动物的暴力行为常常与攻击性的功能性形式相混淆。目前，动物的暴力行为主要被认定为定量行为（一种升级的、病理性且异常的攻击形式，其主要特征为攻击潜伏期短，以及长期且频繁的以伤害为导向的冲突行为）或定性行为（其特征为攻击咬伤对手身体的脆弱部位，且无论环境或对手的性别及类型如何，均进行与环境无关的攻击）。因此，确定暴力行为的操作性定义不仅有助于理解其与适应性攻击形式的潜在差异，还有助于为两者选择合适的动物模型。我们通过借鉴人类和其他动物攻击性及安抚行为的研究，从理论上探讨了这个问题。我们还通过将我们的研究结果与其他目前可用的潜在暴力啮齿动物模型进行比较，为高攻击性小鼠的暴力行为提供了实证证据。以下是暴力行为特有的特征，即：（1）预升级/仪式性行为水平较低；（2）尽管对手呈现顺从的仰卧和蹲伏/战败姿势，但攻击持续时间立即升级且撤离率低；（3）在中性环境中，对熟悉/不熟悉的雌性、麻醉的雄性及对手进行与环境无关的无差别攻击；（4）攻击咬伤朝向对手的脆弱身体部位，导致严重受伤；（5）反复攻击后前额叶血清素（5-HT）水平较低；（6）在短攻击潜伏期（SAL）小鼠中独特地发现基础心率较低且下丘脑-垂体-肾上腺皮质（HPA）轴反应低下，这表明动物的暴力行为与适应性攻击之间存在质的差异。
