Intruders of differing reproductive status alter aggression differentially in early and late pregnant mice

Independent groups of early and late pregnant mice, housed individually, were observed with an intruder in their home cage. The intruders were either males, virgin, early, or late pregnant females. Male intruders were sniffed less, but more frequently and more severely attacked, than any type of female intruder, both by early and by late pregnant residents. While early pregnant females behaved similarly with the three types of female intruders, late pregnant animals treated them differently: they showed practically no aggression to late pregnant intruders, more to early pregnant ones and were most aggressive towards virgin female intruders. The possible relation of these findings to reproductive behaviour is discussed.     

The medial amygdala: Serotonergic inhibition of shock-lnduced aggression and pain sensitivity in rats

Two aspects of the amygdaloid complex (corticomedial and basolateral) were examined with reference to serotonergic inhibition of shock-induced aggression. Fighting was significantly depressed by serotonergic stimulation (5-HT, 10 μg bilateral) in the corticomedial amygdala while serotonergic blockade (methysergide, 5 μg bilateral) in this region increased levels of fighting. No consistent effects were obtained with serotonergic manipulation of the basolateral amygdala. Further investigation revealed that the state of serotonergic activity in medial amygdaloid sites was associated with concomitant alterations in the animals' sensitivity to footshock. Results are discussed in relation to a) a general inhibitory role of serotonin in behavioural mechanisms and b) a dopaminergic-serotonergic balance for behavioural arousal involving medial amygdaloid nuclei.     

Outline of a denotative definition of aggression

Aggression is defined as generic assertiveness which includes both constructive and destructive behaviors. An attempt is then made to classify the distinctive operational settings (phenotypic situations) which trigger aggression. The classes of such settings are: 1) privation - the frustration of vital needs and the frustration due to inner conflict of needs; 2) conflict (social) - situation-specific competition and intragroup rivalry for dominance; and 3) victimization — predator-prey relations and vandalism per se. Critical questions which emerge from the definition and classification are posed.     

Some adrenal correlates of aggression in isolated female mice

Forty-six female mice (CFW) were isolated for a period of 23 weeks. The effect of isolation on fighting behavior was tested weekly by introducing a naive brown female mouse into the subject's home cage. Total leucocyte counts were obtained at 8 and 14 weeks of isolation. The appearance of leucopenia was used as an index of elevated adrenocortical activity. After 23 weeks of isolation all animals were sacrificed by decapitation. Plasma was collected for corticosterone assay, and paired adrenals were used to assay catecholamine levels. On the basis of the frequency and/or the absence of fighting, the mice were segregated into fighters (n = 22) and non-fighters (n = 17). Analysis of the data by Pearson's product moment correlation and Student's t-test showed that elevated sympathetic-adrenal activity was positively correlated with aggression and that elevated adrenocortical activity was negatively correlated with aggression.     

Effects of D- and L-amphetamine on the predatory behavior of Southern grasshopper mice,onychomys torridus

Adult male and female southern grasshopper mice (Onychomys torridus) were tested for predatory aggression toward cricket prey 1 hr after single injections of d-amphetamine (1 or 10 mg/kg) or 1-amphetamine (1 or 10 mg/kg). At the lower dose, d-amphetamine decreased feeding behaviors, while I-amphetamine altered attack-related behaviors. At the higher dose, both stereoisomers appeared to be equipotent in significantly decreasing 5 measures of predatory aggression. These results suggest that brain dopamine and norepinephrine play important roles in the regulation of predatory aggression of Onychomys torridus.     

The effects of alcohol and delta-9-tetrahydrocannabinol on human physical aggression

Forty male undergraduates were provoked following their ingestion of high or low doses of either alcohol or delta-9-tetrahydrocannabinol (THC). The expression of physical aggression was related to the quantity of alcohol ingested. The high dose of alcohol instigated more intense aggression than the low dose. The high dose of THC, on the other hand, did not increase aggressive behavior. In fact, it tended to produce a weak suppression effect.     

大学生因特网成瘾障碍的研究

本研究根据目前广泛认可的因特网成瘾障碍(Internet Addiction Disorder,IAD)诊断标准自编问卷,调查了上海市6所高校370名大学生的上网情况。结果表明:(1)自编问卷质量的各指标皆良好,问卷具有较好的稳定性和准确性。(2)上海市大学生IAD的发生率大约为8.1%。(3)男生比女生、理科比文科、大二年级比其它年级的学生陷入网络的程度深。(4)上网者每周的上网时间、使用网络工具的数量、上网动机的数量与使用网络的程度相关。(5)IAD者在网络使用的特点上明显不同于非IAD者(N-IAD者)。     

Reactive and proactive aggression: Similarities and differences

The purpose of the current study was to elaborate the nomological net surrounding the constructs of reactive (RA) and proactive aggression (PA). Typically examined in the context of children, the current study utilized a sample of 211 young adults to examine the relations between reactive and proactive aggression and measures of general personality and social information processing, as well as maladaptive behavioral correlates such as crime, substance use, and riskier sex. Both raw and residualized scores were examined. Using raw scores, the primary differences between RA and PA were related to Neuroticism (i.e., RA more strongly related) and externalizing behaviors (i.e., PA more strongly). The authors comment on the similarity of findings when using raw scores and the divergence of findings using residualized scores and argue for a cautious interpretation of differences based on residualized scores. The authors conclude that the role of Neuroticism warrants further exploration as a means for understanding the heterogeneity of aggressive behavior.     

A Longitudinal Study of Relational Aggression, Physical Aggression, and Children's Social–Psychological Adjustment

Although great strides have recently been made in our understanding of relational aggression and its consequences, one significant limitation has been the lack of prospective studies. The present research addressed this issue by identifying and assessing groups of relationally aggressive, physically aggressive, relationally plus physically aggressive (co-morbid), and nonaggressive children during their third grade year in elementary school and then reassessing them a year later, during fourth-grade (N = 224, 113 girls). Two aspects of social–psychological adjustment were assessed during both assessment periods including internalizing difficulties (i.e., withdrawal, depression/anxiety, and somatic complaints) and externalizing problems (i.e., aggressive behavior, delinquency). It was revealed that the strongest predictor of future social–psychological adjustment problems and increases in these problems from third to fourth was the combination of relational and physical aggression. Relational aggression also contributed unique information, relative to physical aggression, in the prediction of future maladjustment. Implications of these findings for future research and prevention efforts, particularly for aggressive girls, are discussed.

The gendered nature of career related learning experiences: A social cognitive career theory perspective

The learning experiences questionnaire (LEQ; Schaub & Tokar, 2005) was used to examine learning experiences as they relate to SCCT (Lent, Brown, & Hackett, 1994) across the Holland (1997) RIASEC typology. In particular, differences in men’s and women’s career related learning experiences were examined. A sample of 319 undergraduates at a public Midwestern university completed an online survey. Gender differences were observed in reported levels of some learning experiences; similar to prior findings for self-efficacy and interests, women reported more learning experiences in the Social domain, and men reported more experiences in the Realistic and Investigative domains. Results also supported that more reported learning experiences in a given domain relate to higher self-efficacy and outcome expectations in that domain.