Individual differences in the study of human aggression

Excessive concern for simplicity has often led us to underestimate the complexity of aggression. Over the years, several scales related to aggression have been identified and validated both on adults and on children. Ultimately, two main higher order dimensions, emotional responsivity and proneness to aggression, repeatedly emerged in a series of second-order factor analysis. These dimensions are rather similar to two of the big five factors of personality: neuroticism/emotinal stability and hostility/agreeableness, respectively. Several studies corroborate the plausibility of a higher level bidimensional conceptualization of aggression that, while preserving the heuristic validity of looking for more specific constructs of aggression, can link the field of aggression to the field of personality. © 1994 Wiley-Liss, Inc.     

Aggression and testosterone: Testing a bio-social model

Based upon reports of a positive correlation between circulating testosterone levels and aggression, we draw upon evolutionary psychology to place the action of testosterone in a broader perspective. We propose that testosterone affects competitive status-seeking and that under certain circumstances (including youth) this is expressed as aggression. Involvement in aggression in turn is associated with adherence to an instrumental social representation of aggression which justifies aggression as a means of imposing control over others and increasing self-esteem. Measures of salivary testosterone, masculinity, preferred social representation of aggression, and multiple aggression scales were collected from an undergraduate sample of 119 men. An Aggression factor was derived from principle components analysis of the aggression measures. The strongest correlates of Aggression were holding an instrumental social representation of aggression and youth. Testosterone showed no significant relationship to the single or aggregate measures of aggression or to any of the other psychometric measures. We suggest ways in which previous work may have over-estimated the strength of the association between circulating testosterone and aggression and discuss the possible relationships between age, social representation, and aggression. Aggr. Behav. 23:239–238, 1997. © 1997 Wiley-Liss, Inc.     

Review and methodological considerations in research on testosterone and aggression

The present paper reviews studies investigating the possible correlation between testosterone and aggression. First, methodological considerations in testosterone research are outlined. These considerations are used as a basis on which past studies are reviewed. How testosterone is related to various personality dimensions is then discussed, concluding with how testosterone is related to aggression in non-criminal and criminal samples. The paper concludes with the suggestion that testosterone may have a relationship with sexually dimorphic behaviors, in particular aggression.     

Factor analysis of MCMI-II and PACL basic personality scales in a college sample

This study examined factor dimensions common to the eight basic personality scales of the Millon Clinical Multiaxial Inventory-II (MCMI-II; Millon, 1987) and Personality Adjective Check List (PACL; Strack, 1987, 1990). Subjects were 140 college students (65 men and 75 women). MCMI-II weighted raw scores (WRS) and WRS corrected for number of items endorsed true by regression were employed for analysis along with PACL T-scores. Principal components analyses with varimax and direct oblimin rotations were carried out separately on the two sets of MCMI-II and PACL scores. MCMI-II and PACL scales measuring the same personalities were usually correlated most highly with each other, although some divergences were noted. WRS yielded three bipolar dimensions and a fourth unipolar method factor that loaded only the five MCMI-II scales that were strongly correlated with number of items endorsed true. Residual scores yielded a more meaningful set of three bipolar dimensions labeled Social Introversion-Extraversion, Emotionality-Restraint, and Social Dominance-Submissiveness, without the method factor, that were very similar to personality dimensions found separately in the two tests. More research is needed to clarify the response bias issue in the MCMI-II and to further explicate similarities and differences between the MCMI-II and the PACL.     

Factor Analysis of MCMI-II and PACL Basic Personality Scales in a College Sample

This study examined factor dimensions common to the eight basic personality scales of the Millon Clinical Multiaxiat Inventory-II (MCMI-II; Millon, 1987) and Personality Adjective Check List (PACL; Strack, 1987, 1990). Subjects were 140 college students (65 men and 75 women). MCMI-II weighted raw scores (WRS) and WRS corrected for number of items endorsed true by regression were employed for analysis along with PACL T-scores. Principal components analyses with varimax and direct oblimin rotations were carried out separately on the two sets of MCMI-II and PACL scores. MCMI-II and PACL scales measuring the same personalities were usually correlated most highly with each other, although some divergences were noted. WRS yielded three bipolar dimensions and a fourth unipolar method factor that loaded only the five MCMI-II scales that were strongly correlated with number of items endorsed true. Residual scores yielded a more meaningful set of three bipolar dimensions labeled Social IntroversionExtraversion, Emotionality-Restraint, and Social Dominance-Submissiveness, without the method factor, that were very similar to personality dimensions found separately in the two tests. More research is needed to clarify the response bias issue in the MCMI-II and to further explicate similarities and differences between the MCMI-II and the PACL.     

小学教师期望对学生人格的影响:学生知觉的中介作用

以1260名小学生为被试,采用问卷法探讨小学教师期望对人格的影响,以及学生知觉在教师期望对人格影响中的中介效应。结果表明:(1)教师期望各维度与人格的智能特征、认真自控、外倾性和亲社会性均有显著正相关,品行和纪律期望维度与人格的情绪稳定性相关不显著。(2)学业期望对人格的智能特征、外倾性和情绪稳定性预测作用最大,品行期望对认真自控预测作用最大,纪律期望对亲社会性预测作用最大。(3)小学生知觉在教师期望对人格智能特征、认真自控、外倾性、亲社会性影响中起部分中介作用,在教师期望对人格情绪稳定性影响中不存在中介效应。     

Support for religio-political aggression among teenaged boys in Gaza: part II: neuroendocrinological findings

Hormones seem to play important roles in the regulation of human aggression. Multiple studies have confirmed that testosterone (T) levels exhibit complex relationships with aggression, dominance, and/or risk-taking behavior. Some evidence suggests that cortisol (CORT) interacts with T and may also be associated with aspects of mood and aggression. However, almost no research to date has investigated the possibility that these neuroendocrine factors are associated with variations in political attitudes or with political aggression. During the second intifada, we tested the hypothesis that morning salivary T and/or salivary CORT levels might be associated with self-rated aggression or with support for religio-political aggression (RPA) among 14-year-old Palestinian boys living in Gaza. We obtained and averaged weekly 09:00 hr salivary measures of T and CORT for more than 1 month. Averaged morning T levels did not correlate with self-rated aggression, but were positively associated with agreement with the statement "religious ends justify any means," (r = .355, P = .014) and marginally associated with a composite measure of support for RPA (r = .247, P = .094). Average CORT levels were inversely correlated with self-rated aggression (r = -.328, P = .037) and with anger (r = -.373, P = .016), but CORT levels were not associated with support for RPA or with the statement "religious ends justify any means." Acknowledging that a modest sample size and methodological issues necessarily limit confidence in our conclusions, these results may represent the first findings regarding neurobiological correlates of support for political aggression.     

The aggression questionnaire.

A new questionnaire on aggression was constructed. Replicated factor analyses yielded 4 scales: Physical Aggression, Verbal Aggression, Anger, and Hostility. Correlational analysis revealed that anger is the bridge between both physical and verbal aggression and hostility. The scales showed internal consistency and stability over time. Men scored slightly higher on Verbal Aggression and Hostility and much higher on Physical Aggression. There was no sex difference for Anger. The various scales correlated differently with various personality traits. Scale scores correlated with peer nominations of the various kinds of aggression. These findings suggest the need to assess not only overall aggression but also its individual components.     

Validation of a motivation-based typology of angry aggression among antisocial youths in Norway

This article describes the validation of the Angry Aggression Scales (AAS), the Behavior Inhibition System and the Behavior Activation System (BIS/BAS) scales, the reactive aggression and proactive power scales in relation to a Norwegian sample of 101 antisocial youths with conduct problems (64 boys, 37 girls, mean age 15 ± 1.3 years) and 101 prosocial controls matched on age, gender, education, ethnicity, and school district. Maximum likelihood exploratory factor analyses with oblique rotation were performed on AAS, BIS/BAS, reactive aggression and proactive power scales as well as computation of Cronbach's alpha and McDonald's omega. Tests for normality and homogeneity of variance were acceptable. Factor analyses of AAS and the proactive/reactive aggression scales suggested a hierarchical structure comprising a single higher-order angry aggression (AA) factor and four and two lower-order factors, respectively. Moreover, results suggested one BIS factor and a single higher-order BAS factor with three lower-order factors related to drive, fun-seeking and reward responsiveness. To compare scores of antisocial youths with controls, t-tests on the mean scale scores were computed. Results confirmed that antisocial youths were different from controls on the above-mentioned scales. Consistent with the idea that anger is associated with approach motivation, AAS scores correlated with behavioral activation, but only explosive/reactive and vengeful/ruminative AA correlated with behavioral inhibition. Results generally validated the quadruple typology of aggression and violence proposed by Howard (2009).     

A three-factor model of trait anger: dimensions of affect, behavior, and cognition

The structure of trait anger was tested in a study of 24 self-report scales. Exploratory factor analyses in an undergraduate sample (N = 457) yielded a two-factor model (comprising cynicism and aggression) and a three-factor model (representing angry emotions, aggressive behaviors, and cynicism). Subsequent evaluations, including confirmatory factor analyses, indicated that the three-factor model provided the best characterization of the trait anger domain. The three-factor solution was consistent with an "ABC" conceptualization of trait anger, consisting of the dimensions of affect, behavior, and cognition. The three factors showed strikingly different associations with the Big Five personality traits. Angry Affect was most strongly related to Neuroticism, whereas Behavioral Aggression was associated with low Agreeableness. Cynical Cognition represented a blend of neurotic and disagreeable characteristics. Modest mean-level differences were observed between the genders for each factor.     

Some Psychological and Social Attitude Correlates of Northern Ireland University Students' Contact with the Civil Disturbances

Northern Ireland university students' contact with the Northern Ireland civil disturbances was examined with regard to five dimensions: Friends' Contact; Bomb Contact; Confrontation or Riot Contact; Harassment; and Property Damage. Confrontation and Bomb contact dimensions were further investigated in terms of their personality, social attitude, and alcohol use correlates. Since analyses of variance did not differentiate Protestants and Roman Catholics in terms of intelligence, socioeconomic status, age, location of residence (rural-urban), or religious homogeneity of peer group with regard to these two contact dimensions, these two groups were combined in stepwise discriminant analyses. The discriminant analyses suggested that, for both genders, contact with the "troubles" may be conceptualized in terms of a positive feedback loop involving social dissatisfaction and helplessness combining with previous contacts to produce future contacts. Further, having been in a bombing appeared to subdue males, but to produce pro-social aggression in females. The sample consisted of 65 males and 133 females.     

Cultural and sex differences in aggression: A comparison between Japanese and Spanish students using two different inventories

Two self‐report inventories developed to assess different dimensions of aggression, the Aggression Questionnaire and the EXPAGG, were administered to a sample (N = 400) of men and women undergraduates in two Japanese and Spanish universities. The factor structure of scales was assessed using exploratory factor analysis. Both questionnaires showed high correlations between their respective scales. In both cultures, males reported more physical aggression, verbal aggression, and hostility as well as higher instrumental beliefs, whereas females reported more expressive representation than males. Japanese students reported more physical aggression than their Spanish counterparts, who reported more verbal aggression, hostility, and anger and more expressive representation of aggression. Aggr. Behav. 27:313–322, 2001. © 2001 Wiley‐Liss, Inc.     

Evidence of cross‐cultural invariance of the big five personality dimensions in work settings

This article explores the cross‐cultural invariance (construct validity) of two work‐related personality inventories based upon the Five Factor Model (the HPI and the IP/5F). The results show a good convergent and discriminant validity between scales that measure the Big Five personality dimensions. A factor analysis indicates that all personality scales load on the hypothesized Big Five dimensions. Some implications of these findings for the research and practice of personality measurement in personnel selection are discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Perceived victimization moderates self-reports of workplace aggression and conflict.

A sample of 489 employed men between 32 and 36 years old responded to questions concerning rates of having engaged in workplace aggression and conflict. These individuals also completed a personality inventory and questionnaires related to past antisocial behavior and alcohol abuse. Consistent with prior research, workplace aggression and conflict were significantly correlated with particular personality variables (stress reaction, aggression, and control) as well as with general past antisocial behavior and alcohol abuse. Furthermore, these relationships were moderated by the perception of being victimized by others (alienation), with such perceptions strengthening associations between workplace aggression and other risk factors. These interaction effects, which cannot plausibly be attributed to the use of a self-report criterion, could have important implications for understanding and predicting aggression and conflict behavior within organizations.     

Hormonal,anthropometrical, and behavioral correlates of physical aggression in !Kung San men of Namibia

Differences in physical aggression among 114 male !Kung San (bushmen) from Namibia were investigated with regard to sex hormone levels, body dimensions, consumption of alcohol, and degree of acculturation. Subjects were classified from injuries resulting from prior conflicts with mutual physical aggression between the opponents as either violent or nonviolent. The comparison of mean sex hormone values (total serum testosterone, T_ser; serum 5α-dihydrotestosterone, DHT; serum estradiol 17β, E₂; “free,” non-SHBG-bound salivary testosterone, T_sal) and hormone ratios (T_sal/T_ser; DHT/T_ser) did not yield any significant differences between the violent and nonviolent group. However, correlation coefficients of sex hormone levels with the frequency of violent behavior within the group of physically aggressive San men were significantly positive for DHT, T_sal, and T_sal/T_ser (P < .05) while T_ser, E₂, and DHT/T_ser showed only weak positive correlations. Moreover, the violent men exhibit higher mean values in certain measures of physical robustness which may point to a possible pathway of indirect androgen action on human aggression. When the probands were classified according to their drinking habits, usually abstinent men had shown significantly less violent behavior in the past than men who habitually consume alcohol.     

Applicability of olweu' aggression inventory in a sample of chinese primary school children

A sample of Chinese children in Grade 4 (155 boys and 135 girls with an average age of 10.3 years) completed Olweu' Aggression Inventory, an instrument developed for the assessment of aggressive and aggression controlling behavior tendencies in a Western culture. Results indicated that the questionnaire gave quite meaningful information when used with the Chinese children. Two interpretable factors, general aggression and aggression control, were derived; the pattern of factor loadings was essentially the same for boys and girls. The internal consistency reliabilities of the two factor scales were in the 0.80s and 0.70s, respectively. Overall, the findings indicated that there were distinct measurable individual differences among Chinese children in the domain of aggression—in spite of strong societal pressures against aggressive behavior and towards aggression control. However, some results suggested that aggression was a somewhat more global, or less differentiated, phenomenon for the Chinese as compared with the Swedish children. The two main factor scales were related meaningfully to other self report dimensions such as positive attitude to school and negative relations with parents. In all probability, the pattern of findings gave a valid picture of the behavior and attitudes of the Chinese children: By and large they were nonaggressive, well-behaved, ambitious, friendly, prosocial, and exerted strong control over aggressive feelings and behavior tendencies. In possible conflicts with adults, they were likely to take a humble and submissive attitude. These findings agree well with the impressions of Western observers and with what can be expected on the basis of the typical socialization patterns found in the People's Republic of China. Furthermore, quite marked sex differences in aggression were obtained and a partial correlation analysis showed that the higher aggression level of the boys could only to a very limited degree be explained by their lower level of aggression control or inhibitions. Generally, the sex differences in aggression were interpreted to reflect genetic variations in basic predispositions in boys and girls that had been subtly enlarged by more or less clear, sex-linked differences in environmental conditions.     

Sex hormone effects on personality at puberty

In this study we use serum steroid hormone assays and Adjective Check List responses from a representative sample of 102 male and 99 female adolescents to examine the relations between hormones, personality, and sexual behavior. We address two questions: (a) Does pubertal testosterone (T) cause sex dimorphism in personality? (b) Do pubertal hormones affect sexual behavior indirectly through effects on personality? Exploratory factor analysis of the Adjective Check List generated a factor common to male and female adolescents that correlated highly with T. However, male and female subjects did not differ in their mean level on this factor or in the correlation of this factor with T. In spite of the large sex difference in T, the girls were much more sensitive than the boys on the extracted factor to differences in T. We conclude that the answer to both questions is probably no.     

A general factor of personality,social desirability,cognitive ability,and the survey of work styles in an employment selection setting

How a general factor of personality (GFP) correlated with employment screening measures in an applied setting was examined. Participants were 540 adult insurance sales job applicants who completed scales from two personality measures, the five scales from the Survey of Work Styles (SWS), an intelligence measure, and a social desirability scale. A joint factor analysis of the personality questionnaires produced four first order factors. A single GFP was also extracted. Strong correlations were found between some of the personality factors and the SWS scales. Strong significant correlations were found between the GFP and three of the four personality factors with social desirability. Neither the GFP nor the personality factors correlated significantly with cognitive abilities.     

Self-reported use of different forms of aggression in late adolescence and emerging adulthood

Two studies investigated the psychometric properties of a self-report measure of commonly recognized forms of aggression (FOA) that could be used to efficiently gather aggression data in large samples. EFA and CFA in Study 1 suggested that a five-factor model (Physical, Property, Verbal, Relational, and Passive-Rational) best represented the data across high school and college students. However, factor analyses in Study 2 using an ethnically diverse university sample revealed a four-factor solution (combining Physical and Property items). As a confirmation of the construct validity of FOA, physical and property aggression were lower, and verbal and passive-rational aggression were higher in college versus high school students. Gender differences were observed across FOA subscales, except relational aggression. FOA subscales correlated as expected with other anger and personality scales. Overall, the data revealed adequate psychometric properties for the FOA and suggest that current category distinctions (e.g., direct-indirect) may not adequately account for different forms of aggression. Researchers may want to reevaluate these categories.