An aggression machine II. Interindividual differences in the aggressive defence responses aroused by varying stimulus conditions

PitkÄnen, L. An aggression machine. II. Interindividual differences in the aggressive defence responses aroused by varying stimulus conditions. Scand. J. Psychol., 1973, 14, 65–74.-The subjects, six aggressive and nonaggressive groups of ten 9-year old boys, selected by rating method, were tested with an "aggression machine" (PAM) constructed by the writer. The varying stimulus conditions included two situations of impulsive aggression and six variations of specified attackers. The results showed that (1) the larger part of the variance of the intensity of aggression in the PAM was accounted for by the situational variations than by interindividual differences in coping with thwarting situations as measured by a rating method. (2) The overtly aggressive boys showed strong discrimination between the situations, while the overtly nonaggressive boys were quite insensitive to situational variations. (3) The intensity of aggressive defence towards a boy of the same age correlated most highly with rated aggressiveness. (4) The latency, duration, and number of aggressive responses did not vary as easily as the intensity according to situations.     

An aggression machine: IV. Concurrent and predictive validity over ten years

The subjects (60 boys) were drawn from the sample of a longitudinal study of social development to represent extremely aggressive, anxious, constructive, and submissive patterns of behaviour at the age of 8. A year later they were tested with an aggression machine (PAM). This allows variation of the intensity of both aggressive attack and defence in different stimulus conditions. The intensity of defensive aggression towards different attackers as well as the response style variables, latency, duration, and number of responses were correlated with observed and self-reported data at the ages of 8, 9, 14 and 19. The results showed that the intensity of aggression toward a same-sex peer had the highest validity. Opposite sex and authority figures as attackers called up other associations and motives, such as conflicts with the mother and anxiety. From the response style variables the highest validity was obtained for reaction time. This correlated with constructive behaviour.     

The impact of non‐aggressive behaviour early in aggressive interactions: Sex differences in direct and indirect aggression in response to provocation

Using an adapted form of the Taylor competitive reaction time task (TCRT: Taylor, 1967), we examined the effect of initially non‐aggressive behaviour during aggressive encounters. Specifically, if a person is initially non‐aggressive, but becomes more aggressive later, does an opponent respond more or less aggressively in response? Participants (N = 148) played a competitive reaction time task against a bogus partner, who was either initially non‐aggressive, or initially moderately aggressive, and then delivered increasingly loud noise blasts to participants on trials when the participant lost. Both direct (noise blasts delivered to the partner) and indirect aggression (damage to partner's reputation) were assessed. The impact of whether or not participants expected to meet the partner on direct and indirect aggression was also examined. All participants reduced their direct aggression towards an initially non‐aggressive partner and a partner they expected to meet. However, for females, the switch from initial non‐aggression to later aggression generated a negative evaluation of the partner, exhibited by indirect but not direct aggression.     

A social identity approach to explaining children's aggressive intentions

This study explored the effects of group norms, intra-group position, and age on the direct and indirect aggressive intentions of 247 children (aged 5.50 to 11.83 years). Participants were assigned to a team, with team norms (aggression vs. helping) and the child's position within the team (prototypical vs. peripheral–prototypical vs. peripheral) manipulated. Results showed that children in the aggressive norm condition reported greater aggressive intentions than those in the helping norm condition, although, when age was considered, this effect remained evident for younger, but not older, children. Similarly, intra-group position influenced the aggressive intentions of younger children only. For these children, when group norms supported aggression, prototypical members and peripheral members who anticipated a future prototypical position reported greater aggressive intentions than peripheral members who were given no information about their future position. The implications of these findings for understanding childhood aggression, and for intervention, are discussed.     

Attacker's intent and awareness of outcome,impression management,and retaliation

Female Japanese students who were engaged in a calculation task were given electric shocks by a female opponent. The subjects were informed that the opponent had an intent to shock them either severely or mildly. In addition, the opponent's awareness of the outcome of attack was independently manipulated: (1) the subjects received shocks whose intensity corresponded to the opponent's intent, (2) the subjects received shocks whose intensity was inversely proportional to the intensity intended by the opponent and were informed that the opponent did not know about it, or (3) the subjects received reversed shocks as in condition (2), but were further informed that the opponent was well aware of it. An ANOVA of the measure of retaliation in terms of the intensity of shocks delivered to the opponent indicated that (1) the subjects showed more aggression of greater intensity against an opponent who apparently had an aggressive intent than the one who did not, regardless of the actual level of shock intensity; (2) when the severe attack failed, the subjects lowered aggression when the opponent was apparently aware of it as opposed to when she was not; and (3) when the subjects received severe shocks accidentally, they increased aggression when the opponent was apparently aware of it compared to when she was not. These results led us to interpret retaliation as being mediated both by the attribution of intent to the attacker and by self-presentation to the attacker and the experimenter.     

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.     

Level of instigation and model similarity as determinants of aggressive behavior

A study was conducted to replicate and extend a finding by Wheeler and Levine [1967] indicating that a dissimilar model was more effective in inducing the contagion of aggression than a similar model. On the basis of recent findings suggesting the circumstances under which dissimilar others are more influential than similar others, the following predictions were derived: When subjects are highly instigated, dissimilar models can influence subjects to be more aggressive than can similar models; when subjects are under a low degree of instigation similar models will influence subjects to be more aggressive. Subjects presented their point of view on a case study in a three-person group discussion setting. Then subjects heard the second person (instigator) attack their position in a highly abusive or slightly abusive manner (High vs Low Instigation). Next subjects heard a third person, whom they had been led to believe was similar or dissimilar to themselves, attack the instigator (Similar vs Dissimilar Model). Finally subjects had an opportunity to express their feelings to the instigator. The results supported the predictions.     

Aggression and power restoration: The effects of identifiability and timing on aggressive behavior

The study was designed to demonstrate that one function of aggression is the restoration of power. It was predicted that, after an individual had his power reduced, greater aggression would be emitted when the individual could be identified as the attacker by his victim than when he could not. It was felt that only when the aggressor was identifiable could he completely restore his power vis-à-vis the victim. A second aim of the study was to investigate the effects of timing of aggression on the intensity of aggression. It was predicted that in a learning situation, if aggression were utilized solely as a teaching device, greater aggression would be emitted by the “teacher” when the “learner” made mistakes early as opposed to late in the task. However, if the individual were motivated to restore his power by aggressing, greater aggression would occur when the mistakes were made late since having to wait should frustrate the teacher's desire to restore power through aggression. The design of the study was a 2 × 2 × 2 factorial in which subjects were either insulted or not, given the opportunity to aggress either anonymously or when clearly identified, and able to aggress either early or late in a learning task. The results supported the power-restoration hypothesis: Subjects who were insulted aggressed more when identifiable than when anonymous. Also, there was greater aggression in the early as opposed to late conditions under all circumstances except in the insultidentifiable condition.     

An aggression machine v. determinants in reactive aggression revisited

The relations between reactive aggression, situational cues, and emotion regulation were examined by means of the Pulkkinen Aggression Machine (PAM) task. In the PAM, provocation and response were systematically varied under two conditions: the impulsive aggression condition and the controlled aggression condition. In the impulsive condition, no information about the attacker was provided, while in the controlled condition the attackers were specified in terms of sex, age, and physical strength. The task was administered to 109 children aged 8 to 13 years. Boys (n = 61) and girls (n = 48), as well as subgroups of Adjusted (n = 67) and Maladjusted (n = 26) children were compared. The results confirmed earlier findings showing that there is a strong relationship between attack and response intensity. However, this relationship was consistently modified by the effects of situation and personality‐related variables. This meant that, while for the impulsive condition response intensity was closely tied to stimulus intensity, in the controlled condition this effect was modulated by the characteristics of the opponent: the more equal the opponent the stronger the retaliations displayed. The Maladjusted children reacted more intensively in the impulsive condition and to minor provocation in the controlled condition than the Adjusted children. This suggests that the intensity of the elicited aggression in the Maladjusted group was particularly dependent on contextual rather than internal control. Aggr. Behav. 27:430–445, 2001. © 2001 Wiley‐Liss, Inc.     

Offence and defence in fights between young pigs (Sus scrofa)

Fights were observed between young, unacquainted, domestic pigs. These fights were described in terms of the frequency of bites and the time spent in each of five spatial configurations of the animals. Depending on the rate that bites were given or received, each spatial configuration was characterized as resulting from offence or defence by one of the pigs. Bites were mainly directed at the head and ears, and defensive moves placed these areas out of reach. The most effective offensive move was an attack from the side. Pigs that lost fights tended to turn away from such attacks: winners were as likely to turn towards the attacker. Whether turning away is submission or simply defence is not clear. Factor analysis showed that fights could be described on three dimensions: offence by the loser along with mutual offence and mutual defence: offence by the winner and defence by the loser: and defence by the winner. Long fights involved much offence by the loser and defence by the winner: short fights involved much defence by the loser. When the pigs met again after 24 h, the fights were shorter and involved less offence and more defence by the loser. The transitions between the configurations reflect a balance of offence and defence by the pig responsible making for the transition. This balance is, in turn, affected by attacks from the opponent, fatigue, and the pig's assessment of its relative fighting ability. Retaliation against attacks is partly responsible for the persistence of fighting.     

Reactive and proactive aggression as meaningful distinctions at the variable and person level in primary school‐aged children

Reactive and proactive aggression is a dichotomous classification of aggression in adults and children. This distinction has been supported by a number of variable‐based and factor analytic studies. Due to high inter‐correlations, however, the reactive—proactive aggression distinction may not be entirely useful for understanding how group or individual aggressive behavior varies in children and adolescents. Drawing on a sample of primary school‐aged children (N = 242) aged 7–12 years, this study sought to determine whether reactive and proactive aggression could be distinguished at the variable‐level and the person‐level in children. Exploratory Factor Analysis of data from an aggression instrument measuring both functions and forms of aggression, found a two‐factor construct of aggression constituted by a reactive and proactive aggression factor. A person‐based analysis was then conducted after classifying children according to the presence of reactive and/or proactive aggression. Discriminant function analysis was used to discern whether classifications on the basis of aggression function produced meaningful distinctions in terms of antisocial traits and emotional valence and intensity measures. Two functions were identified which distinguished children with different combinations of reactive and proactive aggression. Reactive‐only aggressive children were defined primarily by high levels of impulsivity, while proactive‐only children were defined primarily by higher levels of antisocial traits. Children high in both types of aggression exhibited both the presence of antisocial traits and impulsivity. Contrary to recent findings, this suggests that differences in aggression functions remain meaningful at the person level in children. Implications for interventions are discussed.

     

Moral approval of aggressive acts: A preliminary investigation

A questionnaire was used to investigate 1) the approval of various kinds of aggressive behaviour under different specified circumstances and 2) the arousal of feelings of aggression in imagined situations. In addition, an attitude test was presented which discriminated between the two highest of Kohlberg's levels of moral reasoning [1969]. The subjects were a very varied group of 83 adults (aged 17–68 years) from municipal evening courses in Finland. Aggression was most approved when it was given altruistic purpose. Self-defense was rated as the second highest justification for aggression. Aggression was found least legitimate when the reasons were emotional (drunk, rage). The justification of some types of aggressive behaviour were dependent on the conditions under which they occurred, whereas others appeared independent. Killing and torture were the most disapproved kinds of aggressive behaviour. Another's attack was the most powerful instigator of feelings of aggression, whereas frustration seemed relatively unimportant. Females approved of emotional expressions of aggression to a greater extent than did males. The moral test did not correlate with approval of aggression in general, but a couple of more specific predictions about the effects of level of moral reasoning on attitudes to socially sanctioned forms of aggression were tentatively confirmed.     

Group norms,intra-group position and children's aggressive intentions

This study aimed to explore the peer group's role in childhood aggression. Participants (N = 356), aged 8.92 to 13.67 years (M = 11.22, SD = .96), were asked to pretend that they had been placed in a team and were then provided with information regarding their team's norms (aggression vs. helping) and their position within the team (prototypical vs. peripheral). Subsequently, participants were asked to rate the likelihood that they would directly or indirectly aggress towards another team. When compared to children in the helping norm condition, those in the aggression norm condition reported a significantly higher likelihood of engaging in direct and indirect aggression. For indirect aggression, prototypical members of aggressive groups also reported being more likely to engage in such behaviour than peripheral members of these groups did. Further, peripheral members of aggressive groups reported a greater likelihood of engaging in indirect aggression than either peripheral or prototypical members of helping groups. The contribution of these results to our understanding of the group mechanisms underlying childhood aggression is discussed.     

Laboratory measures of aggressive responding in male parolees with violent and nonviolent histories

Males on parole were recruited into a study to determine the external validity of the ©Point Subtraction Aggression Paradigm, a laboratory procedure for measuring human aggressive responding. Subjects were assigned to either a violent or nonviolent group based on their criminal record and the Brown History of Violence Questionnaire. Subjects participated in six 25-min sessions and completed a series of questionnaires. During the laboratory sessions subjects were given two response options: 1) Pressing button A to accumulate points exchangeable for money, and 2) pressing button B which ostensibly subtracted points from another fictitious person. Responding on button B was defined as aggressive since it resulted in the ostensible delivery of an aversive stimulus to another person. Results indicated that the subjects in the violent group emitted significantly more aggressive responses than subjects in the nonviolent group. The two groups also differed on psychometric measures of aggression. This study provides external validity for this laboratory measurement of human aggressive responding, even among males with very similar backgrounds. © 1996 Wiley-Liss, Inc.     

Gender differences in the negative affective priming of aggressive behavior

The negative affective priming of aggression was examined across different aversive contexts (general stress exposure and frustration) with a laboratory aggression paradigm that measured the intensity of shocks participants delivered to a putative employee. Participants' emotional responses were gauged via startle eyeblink reactions and self-report mood ratings. Aside from gender differences in overall aggression, men but not women exposed to general stress showed significant increases in aggression across blocks. However, frustration produced increases in aggression in both genders. Although both genders showed robust startle increases during stress, startle activation was related to increases in aggression in men and decreases in aggression in women. These findings suggest that general stress and experiences of negative emotion trigger physical aggressive responses more strongly in men than in women.     

Spontaneously hypertensive Wistar-derived male rats are more aggressive than those of their normotensive progenitor strain

We compared a group of spontaneously hypertensive rats (SHRs) to a group of Wistar-Kyoto (WKY) rats on each of the three most commonly studied forms of aggressive behavior in rats: muricide, intraspecific aggression, and shock-induced fighting (SIF). A significantly higher proportion of SHRs were muricidal; they also fought more at the lowest shock level. A trend for a higher incidence of intraspecific offense behaviors by SHRs was not significant. SHR flinch and jump thresholds were lower than the respective WKY thresholds. Although there were no significant correlations between shock thresholds and any aspects of SIF, the possibility that strain differences in shock sensitivity may contribute to differences in SIF cannot be ruled out. Within strains, there were no correlations among the different forms of aggression. Several different inherited characteristics may be associated with the accentuation of different forms of aggression in SHRs.     

Desensitization to media violence: links with habitual media violence exposure, aggressive cognitions, and aggressive behavior

This study examined the links between desensitization to violent media stimuli and habitual media violence exposure as a predictor and aggressive cognitions and behavior as outcome variables. Two weeks after completing measures of habitual media violence exposure, trait aggression, trait arousability, and normative beliefs about aggression, undergraduates (N = 303) saw a violent film clip and a sad or a funny comparison clip. Skin conductance level (SCL) was measured continuously, and ratings of anxious and pleasant arousal were obtained after each clip. Following the clips, participants completed a lexical decision task to measure accessibility of aggressive cognitions and a competitive reaction time task to measure aggressive behavior. Habitual media violence exposure correlated negatively with SCL during violent clips and positively with pleasant arousal, response times for aggressive words, and trait aggression, but it was unrelated to anxious arousal and aggressive responding during the reaction time task. In path analyses controlling for trait aggression, normative beliefs, and trait arousability, habitual media violence exposure predicted faster accessibility of aggressive cognitions, partly mediated by higher pleasant arousal. Unprovoked aggression during the reaction time task was predicted by lower anxious arousal. Neither habitual media violence usage nor anxious or pleasant arousal predicted provoked aggression during the laboratory task, and SCL was unrelated to aggressive cognitions and behavior. No relations were found between habitual media violence viewing and arousal in response to the sad and funny film clips, and arousal in response to the sad and funny clips did not predict aggressive cognitions or aggressive behavior on the laboratory task. This suggests that the observed desensitization effects are specific to violent content.     

日常环境中的暴力暴露对攻击行为的长期影响:一个有调节的中介模型

以850名大学生为被试,探讨日常环境中的暴力暴露与攻击行为的关系,并在此基础上提出一个有调节的中介模型,考察攻击性信念的中介作用和人际信任的调节作用。结果发现:(1)日常环境中的暴力暴露对攻击行为有显著的正向预测作用;(2)攻击性信念在日常环境中的暴力暴露与攻击行为的关系中起部分中介作用;(3)攻击性信念的中介作用会受到人际信任的调节。对于低人际信任个体,攻击性信念起部分中介作用;对于高人际信任个体,攻击性信念的中介效应不显著,日常环境中的暴力暴露对攻击行为只有直接作用。