A developmental-genetic analysis of aggressive behavior in mice: IV. Genotype-environment interaction

To assess the extent of plasticity in behavioral development after directional selection for aggressive behavior, male mice were reared and tested in selected social rearing and testing conditions. After four generations of selective breeding, the lines differed in all attack measures when tested in a dyadic assessment following isolation rearing. Line-specific effects of isolation vs. group rearing were demonstrated, and longitudinal studies showed the ontogenetic pattern of difference between lines to be substantially changed by conditions of rearing and testing. The social-interactional processes that might produce the developmental genotype-environment interaction were investigated. Line-specific interaction patterns within long-established sibling groups predicted aggressive behavior in cross-situational dyadic assessments. Group rearing attenuated most line differences in aggressive measures, but the high-aggressive line was more likely than the low-aggressive line to persist in attacking over consecutive days of observation. Cross-fostering in early development did not significantly change adult aggressive behavior. Some implications of a developmental-genetic approach to the study of social interactions are discussed.     

Androgens and aggressive behavior in primates: A review

This review deals with possible central and peripheral effects of androgens upon primate aggressive behavior. One problem that clouds interpretation of experimental work is that measurements of dominance have often been employed, such as competition tests for food and water. Such measures often do not correlate with those obtained by quantifying aggressive interactions. It should be remembered that very few of the 188 primate species have been studied experimentally and that great behavioral and physiological diversity occurs within the order. Therefore, generalizations about the effects of androgens upon aggressive behavior in primates (including man) should be made with caution. Testosterone has an organizing influence upon the foetal brain of rhesus monkeys and may affect the development of neural mechanisms which govern aggression in males. More data are required on primates, however, since rhesus monkeys show some important differences from rodents as regards the effects of androgen upon sexual differentiation of the hypothalamus. In future, marmosets may provide a suitable model for such studies, because there is evidence that sexual differentiation of brain by androgen occurs postnatally in these monkeys. At puberty, male primates show a variety of behavioral changes and, during adulthood, males of seasonally breeding species may be more aggressive during the mating season, when testosterone levels are maximal. This does not indicate a causative relationship between testosterone and aggressive responses, because castration and androgen treatments have little effect upon aggression in prepubertal or adult males of several primate species. Androgens have pronounced effects on sexual responses in adult male monkeys, but their central effects upon aggression are much less important than among rodents. Elec trical stimulation of hypothalamic pathways has been employed to evoke aggressive behavior in marmosets and rhesus monkeys. In the rhesus, preliminary evidence indicates that such pathways show some sensitivity to androgens. In rodents it is known that these areas are richly supplied with monoaminergic neurons, which play an important role in aggressive behavior. There is little evidence on primates, however, and this remains a crucial topic for future research. Peripheral effects of androgens should also be considered. Many prosimians and New World monkeys use scent-marking behaviors and, in males, androgen-dependent chemical cues may be involved in sexual recognition and territorial behavior. This possibility awaits investigation. Finally, plasma testosterone levels may alter as a function of aggression itself; thus levels decrease if male rhesus monkeys are defeated by conspecifics. This might occur because neural events associated with giving (or receiving) aggression also influence pituitary function and hence alter gonadal testosterone secretion. Theoretically, it is possible that such changes in circulating testosterone might affect aggressive behavior via a feedback action on the brain, but the experimental evidence does not support such a view.     

A sensory contact model for the study of aggressive and submissive behavior in male mice

The technique for simultaneous development of aggressive and submissive behaviors as a result of successive experiences of defeats or victories in daily intermale confrontations in male mice permanently living under sensory contact conditions is offered for behavioral, pharmacological, and neurophysiological studies of mechanisms of agonistic social relations. Distant sensory contact is achieved by placing a pair of males into a common cage separated by a transparent partition with holes permitting visual contact and the individuals perceiving each other's odors but preventing any physical at contact all times except for 10-min daily tests. These conditions essentially elicit aggression in winner males and quickly result in submission by losers of the same strain of mice. The meaning of consecutive stages of the technique, the problem of controls, and applications of this model are discussed.     

Retracted: Effects of cartoon violence on aggressive thoughts and aggressive behaviors

This article reports on an experiment designed to test whether the cartoon manipulation leads to significant increases in aggressive thoughts and aggressive behaviors among Chinese children (n = 3,000). Results indicated that brief exposure to a violent cartoon triggered higher aggressive thoughts and aggressive behaviors than a nonviolent cartoon. Females displayed higher aggressive thoughts and aggressive behaviors than males in a nonviolent cartoon condition, while males displayed higher aggressive behaviors than females in a violent cartoon condition. Mediation analysis suggested that the effect on aggressive behaviors was mediated by aggressive thoughts. The findings imply that cartoon developers, parents, and teachers should develop cartoons that inhibit children's aggressive thoughts to avoid aggressive behaviors. Females are the key group for the prevention and intervention of aggression in a nonviolent cartoon context, while males are the key group for the prevention and intervention of aggression in a violent cartoon context.     

The reinforcing properties of aggressive vs nonaggressive social interactions in isolated male ICR mice (Mus musculus)

Isolated male ICR mice in a T-maze consistently selected the goal box which enabled them to fight another mouse if the alternative goal box allowed no social interaction (Experiment 1). However, if the alternative choice enabled the isolated mice to interact with another mouse through a mesh screen which prevented fighting, the preference for the opportunity to fight did not appear (Experiment 2). Because the visual, olfactory, and auditory stimuli available through the screen appeared to be as attractive as the stimuli provided by the additional opportunity to fight, it is not necessary to conclude that the stimuli reinforcing the choice behavior in Experiment 1 were provided by fighting. Since there is no compelling reason to conclude that fighting is a primary reinforcer for these isolated mice, it is not necessary to argue that the high incidence of isolation-induced fighting is the reflection of a primary aggressive motive.     

Effects of harsh parenting and positive parenting practices on youth aggressive behavior: The moderating role of early pubertal timing

Prior research indicates that early pubertal timing is associated with aggressive behavior, particularly in the context of adversity as postulated in the contextual amplification hypothesis. However, few studies have examined harsh parenting as the context for the effect of early pubertal timing. Even fewer studies have tested the interactive effect of early pubertal timing and positive parenting on aggressive behavior. In this study, we tested the proposition that early pubertal timing, contrary to the general conception of it as a vulnerability, indexed susceptibility, and thus early maturing individuals were affected more by their environment in a “for better and for worse” manner. The sample consisted of 411 community‐recruited youth aged 11–12 years (51% boys, 80% African Americans). Participants reported Tanner Stages of pubertal development, aggressive behavior and harsh parenting practice of their parents. Puberty scores were standardized with groups of the same age, sex, and ethnicity, and those that scored the top one‐third were defined as early maturing individuals. Parents reported youth's aggressive behavior and their parenting practices towards the youth, including harsh parenting and positive parenting. Early pubertal timing significantly moderated the relationship between harsh/positive parenting and aggressive behavior. Specifically, harsh parenting was positively associated with aggressive behavior to a larger degree among early maturing individuals than among on‐time/late‐maturing individuals. Positive parenting was inversely associated with aggressive behavior but only among early maturing individuals. This study is the first to document support for early pubertal timing as susceptibility to the environmental influences in relation to aggressive behavior. Theoretical and intervention implications are discussed.

     

Effects of age at differential housing and the duration of individual housing/grouping on lntermale fighting behavior and adrenocortical activity in TO strain mice

A study of the effects of the duration of individual and group housing on intermale fighting and adrenocortical activity was conducted in TO strain mice. It was found that fighting and threat increased with progressive isolation up to an asymptote at 56–58 days. ‘Basal’ adrenocortical function differed little under the 2 housing conditions, but after ‘stress,’ mice isolated for short periods, which had not fought when tested for aggression, had lower titers than group-housed counterparts. However, mice that had been isolated for longer periods, and had fought in aggression tests, had higher corticosterone titers than comparable group-housed animals. The effects of a short duration (28–30 days) of differential housing, commencing at different ages, were also studied. The shorter duration adrenocortical changes were largely confirmed. In general, the earlier the age at which the differential housing was imposed, the greater the behavioral differences between animals under each housing condition. It is suggested that this is largely a consequence of a loss of behavioral plasticity in older mice. The data provides little support for the concept of the “isolation stress syndrome,” or for the view that the characteristic fighting exhibited by individually housed mice is a consequence of “social deprivation”.     

Friendly fire: Longitudinal effects of exposure to violent video games on aggressive behavior in adolescent friendship dyads

Research on gaming effects has focused on adolescence, a developmental period in which peer relationships become increasingly salient. However, the impact of peers on the effects of violent gaming on adolescents has been understudied. This study examined whether adolescents’ exposure to violent video games predicted their own and their friend's aggression one year later. Among 705 gaming adolescents, 141 dyads were identified based on reciprocated best friend nominations (73.8% male, M_age = 13.98). Actor‐Partner Interdependence Models indicated that adolescent males’ (but not females’) exposure to violent games positively predicted the aggression of their best friend 1 year later. This effect appeared regardless of whether the friends played video games together or not. The study illustrates the importance of peers in the association between violent gaming and aggression.     

Effects of reactivity to dorsal stimulation and social role on aggressive behavior in laboratory rats

Rats were selected on the basis of reactivity to dorsal tactile stimulation and then tested in a resident-intruder paradigm. While reactivity of residents did not influence the occurrence of agonistic behaviors or wounding of residents and intruders, reactivity of intruders did affect offensive and defensive patterns of interactions and the wounds sustained by residents and intruders. Subsequent to resident-intruder testing, rats were tested for shock-induced aggression. The pattern of the results and the results of additional experiments demonstrated that resident-intruder experience could affect subsequent shock-induced aggressive behavior.     

重复性急性应激对攻击行为的影响及调控机制

关于急性应激对攻击行为的影响, 现有研究多集中于单次急性应激情境下。然而, 相比单次急性应激, 对重复暴露于同一应激源的研究更能反映人们在现实生活中经历的应激事件。与单次应激不同, 重复性急性应激与应激适应有关, 能够节省资源, 具有很强的进化和适应意义, 但目前关于重复性急性应激对攻击行为的影响却知之甚少。鉴于此, 研究运用事件电位相关技术、鼻喷催产素和催产素受体基因型分析方法, 探讨重复性急性应激对攻击行为的影响及内部机制, 并进一步探讨通过内部和外部调控重复性急性应激反应后攻击行为的变化。     

The relationship between aggressive and sexual behavior in male mice: Effects of testosterone and parachlorophenylalanine

The purpose of this study was to clarify the connection between aggressive and sexual behavior with the aid of testosterone propionate (TP) and parachlorophenylalanine (PCPA). Previous studies have indicated that aggressive and sexual behavior are positively correlated, and it has been suggested that both behaviors are related to the level of general arousal. Testosterone has documented effects on both aggressive and sexual behavior. It has been hypothesized that these effects are due to an increased level of general arousal. If this is the case, aggressive and sexual behavior could be restored by administration of drugs excitating the central nervous system, e.g., PCPA. The present study examined the effects of TP and PCPA on aggressive and sexual behavior in gonadectomized male mice. Control animals were injected with sesame seed oil or saline. The level of aggressiveness was assessed by means of dyadic tests with gonad-intact male opponents. For the sexuality tests, a receptive female was placed in the home cage of the experimental male. The results showed that male mice injected with PCPA were more aggressive than the males of the other groups, while the TP-exposed males expressed the most sexual activity. Compared to the control group, the PCPA and TP groups were more active in both the aggression and the sexuality tests. These findings lend support to the hypothesis that the earlier documented correlations between aggressive and sexual behavior could be due to both behaviors being dependent on a certain level of general activation. Aggr. Behav. 24:367–377, 1998. © 1998 Wiley-Liss, Inc.     

The effect of justified video game violence on aggressive behavior and moderated immersion: An experimental approach

The effect of violent video games on aggressive behavior is an important topic in the field of game research. Recently, growing evidence suggests that justified game violence decreases feelings of guilt caused by in-game immoral behavior. However, little is known about the impact on aggressive behavior, and whether other factors moderate this effect. In a two-factor experiment, we tested the impact of justification of video game violence on aggressive behavior, and whether this effect would be enhanced by game immersion. Pilot experiment 1 (N = 60) and pilot experiment 2 (N = 40) demonstrated that the justification of violence and game immersion was successfully controlled by avatar and graphics quality. In the Main experiment, 123 participants played one of four conditions of a video game (2 [justification: justified vs. unjustified violence] × 2 [immersion: high vs. low immersion]) and it was found that participants who played in the justified violence condition reported greater aggressive behavior than those in the unjustified violence condition. In addition, participants who played in high immersion reported greater aggressive behavior than those in low immersion. However, game immersion did not moderate the effects of justified violence. This unexpected effect is likely due to participants' distancing themselves from and identifying less with their violent avatars.     

Differences between two strains of mice,selectively bred for high and low aggressiveness,in the capacity of male odors to affect aggressive behavior

The connection between a genetic disposition for aggressive behavior and the odor signal system in male mice was studied. The males belonged to two strains of mice which have been developed by selective breeding for high- (TA) and low aggressiveness (TNA). Urine from the high aggressive strain (TA), when applied to castrates, stimulated the aggressiveness of NMRI males while TA-soiled bedding suppressed their aggressiveness. In response to male odors from the low aggressive strain (TNA), the NMRI males showed quite contrasting reactions. The results provide evidences of a correlation between the hereditarily determined disposition for aggressive behavior and the odor signal system in TA- and TNA males.     

Teacher escape,avoidance, and countercontrol behaviors: Potential resoponses to disruptive and aggressive behaviors of students with severe behavior disorders

We develop hypothese based on the research literature regarding behavioral responses to aversive stimuli. Specifically, escape, avoidance, and countercontrol responses are presented as teacher behaviors which may occur in the presence of disruptive and aggressive behaviors (aversive stimuli) which, in part, characterize many students with severe behavior disorders (SBD). The potential for teacher escape, avoidance, and countercontrol responses to the detrimental for both teachers and students is presented, as well as suggestions for addressing aversive behaviors of students in ways to reduce the potential detrimental impact.     

儿童和青少年同伴侵害与攻击行为关系的三水平元分析

攻击行为在儿童和青少年的社会、情感和心理适应中发挥着重要作用, 而同伴侵害是儿童和青少年攻击行为一个重要的预测因素。先前的一些研究已经考察了儿童和青少年同伴侵害与攻击行为之间的关系, 但是尚不完全清楚调节效应对二者关系的影响。因此当前研究采用三水平元分析方法检验效应量的可靠性和一系列调节效应。在系统地搜索了2020年10月之前发表的文献后, 当前元分析确定了40项研究, 包括25605名被试, 共计333个效应量。主效应检验发现儿童和青少年的同伴侵害与攻击行为呈显著正相关。此外, 调节效应检验发现同伴侵害变量具有显著的调节作用。与身体侵害相比, 关系侵害与儿童和青少年攻击行为之间的相关更强。儿童和青少年的同伴侵害与攻击行为也受到了地区的调节, 它们之间的关系在亚洲地区比在南美洲地区更强。研究设计也是一个显著的调节变量, 儿童和青少年同伴侵害与攻击行为的相关在纵向研究中比在横向研究中更低。最后, 当前元分析的结果显示同伴侵害的报告者也是一个显著的调节变量。与同伴报告的同伴侵害相比, 教师报告的同伴侵害与儿童和青少年攻击行为之间的相关较高。当前研究的结果指出, 在预防、控制儿童和青少年的攻击行为时应该注意同伴侵害对其的影响。     

Consistency of aggressive temperament in domestic pigs: The effects of social experience and social disruption

Resident‐intruder (R‐I) tests can be used to measure the aggressive temperament of domestic pigs (Sus scrofa), and have previously been shown to predict the severity and persistence of aggression when unfamiliar pigs are mixed. To study the consistency of individual differences in aggressiveness over time, 112 pigs (eight from each of fourteen litters) were given two R‐I tests at each of three ages (46, 80, and 113 days). Pigs were R‐I tested singly in an arena within the home pen, where a smaller unfamiliar intruder pig was introduced to a resident pig. Latency to the first attack by the resident was recorded, and the test was stopped as soon as an attack occurred, otherwise the test lasted five minutes. Pigs from eight of the litters used here had been allowed to mix with another litter prior to weaning (days 10–30; socialised), while pigs in six litters remained in littermate groups (control). To determine whether consistency would survive the effects of social disruption, pigs were mixed into new groups on two occasions between the first and second test, then remained in these groups until the third test. Evidence of consistency was found, despite the social disruption. Socialised pigs were more aggressive than controls, females were more aggressive than males, and certain litters were more aggressive than others. After adjusting for these, consistent differences between individuals were still evident. Consistency was higher between the second and third tests compared to the first and second, possibly because of stable group membership or the effects of age or experience. In support of the idea that social experience improves consistency, socialised pigs were more consistent than controls throughout. Evidence of consistent individual differences in aggressive temperament suggests that breeding or changes to early life experiences could have a long‐lasting influence on aggressive behaviour in pigs. Aggr. Behav. 30:435–448, 2004. © 2004 Wiley‐Liss, Inc.     

饥饿对认知与社会行为的影响及其机制

从心理学视角综述了饥饿对个体认知与社会行为的广泛影响。饥饿会损害一般认知功能, 潜在导致决策与认知偏差, 并引发道德判断标准降低、社会态度改变以及攻击行为增加等现象。在以往研究的基础上, 总结出饥饿影响认知与社会行为内在机制的三种假说：自我损耗说、认知激活说以及协调机制说。最后, 指出当前研究存在着饥饿主观感受差异、测量方法不够准确等问题, 未来研究需要提高饥饿的测量效度, 从生理、心理、社会等多个层面对饥饿影响的机制进行深入探讨。     

Pubertal development and behavior: Hormonal activation of social and motivational tendencies

Adolescence is a time of dramatic changes including rapid physical growth, the onset of sexual maturation, the activation of new drives and motivations, and a wide array of social and affective changes and challenges. This review focuses on behavioral changes in this interval and is organized by the claim that a key set of these adolescent changes are part of a more general re-orientation of social behavior. More specifically we hypothesize that pubertal maturation is associated with the activation of social and motivational tendencies, which in turn influence behavior and emotion in adolescence depending upon interactions with social context. We focus on evidence for two examples of these motivational changes: (1) increases in sensation-seeking (motivational tendency to want to experience high-intensity, exciting experiences) and (2) stronger natural interest in—and pursuit of—contact with peers and potential romantic partners. We consider how these motivational changes contribute to the broader social re-orientation of adolescence, including exploration of social experiences, development of skills and knowledge relevant to taking on adult social roles, individuation from family, and establishment of an individual identity, all of which represent core developmental tasks during this period in the life span ( 9, 16 and 62). The paper also emphasizes the importance of investigating and understanding the direct influences of puberty on behavior and disentangling these from the broader set of changes during adolescent development.