The offensive nature of maternal aggression in mice: Effects of fluprazine hydrochloride

The phenylpiperazine fluprazine hydrochloride was used to test the hypothesis that maternal aggression in laboratory mice reflects offensive motivation. Lactating females (n = 8 per condition) tested for aggression following drug treatment (1.0 mg/kg and 5.0 mg/kg of fluprasine) were significantly less aggressive than saline controls according to all measures used. The findings support the hypothesis that maternal aggression is offensive in nature, and provide no evidence that maternal attack is a mixture of offensive and defensive tendencies.     

Effects of selective breeding for high and low aggressiveness and of fighting experience on odor discrimination in mice

The present study was designed to determine whether male and female mice, selectively bred for high (TA) and low (TNA) aggressiveness, react in different ways when exposed to odors from males of the same strains. The effects of losing or winning fights on odor preferences in the TA males were also studied. The low aggressive TNA males were found to avoid areas soiled by the highly aggressive TA males. The TA males, on the other hand, were most interested in the areas soiled by other highly aggressive TA males. Along with decreasing aggressiveness, losing fights radically changed the odor preferences of the TA males, the soiled bedding from winner TA males now having a strong aversive effect. TNA females preferred the odors of TA males, while the TA females preferred the odors of TNA males. The genotype of the receiver of odor cues is important for the preference choices; this effect can, however, be changed through experience.     

Genetic analysis of “Spontaneous” intermale aggression in mice

“Spontaneous” intermale aggression was investigated in seven inbred strains of mice. A positive interstrain correlation and cross-correlation was found for two indices of fighting intensity, ie, accumulated attacking time and number of attacks. The strain aggressiveness level (percent of mice fighting in each strain) does not correlate with the intensity of aggressive behavior. It has been shown by using a genetical analysis performed on C57BL/6 and BALB/c strains, their reciprocal F₁ hybrids, and back-crosses that these indices of intermale aggression are under different genetic control. Aggressive behavior intensity depends on the additive effects of genes. The control of strain aggressiveness level revealed that a high level of aggressiveness was dominant. No reciprocal effects were found. The level of aggressiveness and the intensity of fighting seem to represent different aspects of aggression and may be controlled by different genetic mechanisms.     

Genotype and environment in the social interactions of wild and domestic “Norway” rats

Wild rats, Rattus norvegicus, (a) trapped as adults or (b) of the second generation in captivity (lab-wild), and domestic rats of two strains, were studied for 28 days in artificial colonies in large cages with attached nest boxes. Controls were kept in mated pairs in small cages. Each colony consisted of six males and six females. The interactions of the males in six colonies of trapped rats were highly “stressful;” 61% died; and most of the survivors lost weight and had greatly enlarged adrenals. In each colony, however, there was a male (an alpha) that gained in weight and spent much time, during the dark hours, in the open on the floor of the cage; and in three colonies there were also other males (“betas”) that gained in weight. The adrenals of alphas and betas weighed about the same as those of the controls. In one of the 12 colonies of domestic rats one male behaved like a wild male; but in the other colonies the males gained in body weight and their adrenal weights resembled those of the controls. In three colonies of lab-wild rats 22% of the males died, but there was no evidence of males of different status. The findings confirm that the “agonistic” behavior of domestic rats is usually much attenuated in comparison with that of the wild type; a number of methodologic implications are discussed.     

Centrally elicited aggressive behavior: A model system for the study of episodic neurobehavioral pathologies?

Studies in which the predatory-like attack of a cat upon a rat has been elicited by electrical brain stimulation have been briefly reviewed with an emphasis on the question of where within the central nervous system such brain stimulation is producing its behaviorally meaningful effects. Two opposing but by no means mutually exclusive views are considered. The first is that brain stimulation elicits this behavior pattern primarily because it affects a specific motivated behavior system that is organized discretely in the midbrain and pons. The second is that forebrain neural activity is modulated in behaviorally significant ways by brainstem stimulation, which elicits predatory-like aggressive behavior in the cat. The possibility that further research on the altered state of central nervous system activity, induced by brain stimulation which elicits aggressive behavior in the cat, may lead to a further understanding of the altered states of central nervous system activity that underlie the aggressive dyscontrol syndrome and other episodic state disorders is discussed.     

儿童期逆境与基因对男性服刑人员攻击性的影响

暴力再犯危险性评估是当今再犯危险性评估工作中的重点, 其中, 攻击性是服刑人员暴力再犯行为稳定的个体因素。对攻击性进行研究, 有助于预防和降低服刑人员在假释或出狱后的暴力再犯行为风险, 关系社会的长治久安。研究表明, 遭受儿童期逆境和携带易感基因(如MAOA-uVNTR低活性等位基因)是导致攻击行为的重要因素。但在现有的研究中, 儿童期逆境的计分方式局限于简单的线性加总, 或所依据的统计模型忽略逆境各维度之间的交互作用和非线性关系; 在服刑人员攻击性的评估中未考虑攻击性的亚类, 而且多使用自报告的量表测评, 这些问题制约了评估的有效预测力。本研究拟通过建立潜在类别模型, 分析男性服刑人员和普通成年人群在儿童期逆境上的亚类; 以实验与问卷测量结果、司法行为记录作为攻击性指标, 揭示儿童期逆境如何影响个体的主动性攻击、反应性攻击及暴力犯罪行为, 重点探讨儿童期逆境潜在类别对主动性攻击和反应性攻击的影响, 以及MAOA-uVNTR、COMT Val158Met、5-HTTLPR基因多态性在其中的调节作用。研究结果有助于找出高攻击性个体的生物遗传指标, 从而发现受儿童期逆境经历影响的易感人群, 为暴力行为的风险预测以及针对暴力攻击行为的行为矫正和相关药物设计提供理论和实证参考, 提高相关工作的效率。     

攻击行为对儿童受欺负的预测：社会喜好的中介效应及性别差异

摘 要 以455名武汉某小学四、五、六年级的儿童为被试,采用同伴提名法、班级戏剧问卷,考察了不同性别儿童的外部攻击、关系攻击、社会喜好与受欺负之间的关系,重点检验了社会喜好在不同类型攻击行为与受欺负之间的中介效应及性别差异。结果表明：（1）小学儿童的外部攻击、关系攻击、社会喜好与受欺负之间均存在显著相关;其中男生的外部攻击与社会喜好、关系攻击与社会喜好的相关系数均显著高于女生;（2）小学儿童在外部攻击和社会喜好维度上得分存在显著的性别差异,男生的外部攻击得分显著高于女生,社会喜好得分显著低于女生;（3）社会喜好分别在外部攻击、关系攻击与受欺负之间存在中介效应,且外部攻击和关系攻击对社会喜好的预测系数均存在显著性别差异,表现为外部攻击、关系攻击对社会喜好的预测作用男生显著高于女生;社会喜好对受欺负的预测系数存在显著的性别差异,表现为社会喜好对受欺负的预测作用女生显著高于男生;而外部攻击和关系攻击对受欺负的预测系数均不存在性别差异。     

教养方式、气质对青少年攻击的影响：独特、差别与中介效应检验

运用“多前因变量－多结果变量”框架, 探讨教养方式、气质对青少年直接和间接攻击有无独特效应与差别效应, 以及规范信念(认为攻击他人是正确和可接受的)在其中的中介作用。660名青少年(平均年龄14.14岁, 女生364人)报告了教养方式、气质特征、攻击信念和攻击行为的情况。多重和多元回归分析表明：(1)教养方式(权威、专制、纵容)对直接攻击独特效应不显著, 气质(意志控制、愤怒挫折、感觉寻求)对直接攻击有独特效应; 教养方式(权威、专制、纵容)和气质(意志控制、感觉寻求)对间接攻击有独特效应。(2)教养方式(权威、专制、纵容)与直接攻击的联系显著弱于其与间接攻击的联系, 而气质(愤怒挫折、感觉寻求)与直接攻击的联系则显著强于其与间接攻击的联系。(3)两类规范信念与两类攻击具有不完全的特异性联系, 而且直接规范在气质(意志控制、感觉寻求)与两类攻击之间具有中介作用, 间接规范在教养方式(权威)与间接攻击、气质(愤怒挫折)与两类攻击之间具有中介作用。因此, 教养方式和气质对不同形式攻击行为的影响不同, 且这种影响可以部分地由规范信念加以解释。     

The heritability of antisocial behavior: A meta-analysis of twin and adoption studies

In this paper, we describe a quantitative summary of 12 twin (n=3795 twin pairs and 3 adoption studies=338 adoptees) published since 1975 which provided 21 estimates of the heritability of antisocial behavior. Medium to large effect sizes were found for genetic influences across studies, with approximately 50% of the variance in measures of antisocial behavior attributable to genetic effects. Although effect sizes did not vary across different definitions of antisocial behavior (criminality, aggression, or antisocial personality), significantly larger estimates of genetic effect were found for severe manifestations of antisocial behavior. The importance of severity was further underscored by the significantly larger effects obtained in studies using clinic-referred samples compared to the effects obtained in studies using volunteer samples. Demographic characteristics of the samples did not influence effect sizes, although studies using more stringent methodology tended to find larger effects. These results must be interpreted in light of the small literature that was suitable for the meta-analysis due to numerous methodological limitations in existing studies.     

Intellectual ability and aggressive behavior in nonclinical-nonforensic males

The purpose of this study was to test the relationship between IQ and physical aggression in a nonclinical-nonforensic male sample in a laboratory setting. Thirty males completed an abbreviated version of the Wechsler Adult Intelligence Scale—Revised. Aggression was measured using a modified version of the Taylor reaction-time (RT) aggression paradigm in which subjects competed on a RT task and both received and delivered shocks to a fictitious opponent in provoking and nonprovoking conditions. Provocation conditions (High and Low) were defined by the intensity of shocks the subjects received. Results demonstrated strong inverse correlations between IQ and aggressive behavior under both High and Low Provocation conditions.