There is convincing evidence that demonstrates traumatic stress and aggressive behavior are highly related among adolescents. The evidence is less clear regarding the direction of this relation. The purpose of this study was to examine the reciprocal longitudinal relations between physical aggression and traumatic stress among a predominantly African American sample of middle school students. Support was found for traumatic stress predicting increased levels of physical aggression across the winter to the spring of the sixth grade for boys and across all waves from the fall of the seventh grade to the fall of the eighth grade for both boys and girls. Conversely, physical aggression during the winter of the sixth grade predicted a decrease in traumatic stress in the spring of the sixth grade for both boys and girls. These findings suggest that interventions may need to incorporate skills that are aligned with trauma-informed care practices in order to reduce traumatic stress and physical aggression among adolescents.

The prevalence of physical aggression increases during adolescence and is associated with negative health outcomes. It is important to identify risk and protective processes for adolescent aggression in the context of the parent-adolescent relationship. The current study examined the potential moderating role of positive parenting at Wave 1 on relations between perceived parental messages supporting fighting at Wave 1 and adolescent aggression based on parent- and student-report at Wave 2. Participants included a sample of 537 adolescents and their primary caregivers, recruited from four sites in the U.S. No significant moderating effects were found. However, parental messages supporting fighting were positively associated with increased student-reported aggression six months later, and positive parenting was related to decreased parent-reported aggression over the same timeframe. Implications suggest that parental messages supporting fighting and positive parenting represent a risk and promotive factor, respectively, in relation to aggressive behavior in early adolescence.

- The relationship between destructiveness and law This thesis deals with the relationship between destructiveness and law. The aim of the thesis is to describe the destructiveness, its manifestations in society and its relationship to the law. To describe the topic I used findings of Fromm, Baumann, Lorenzo, Elias, Arendt, Karstedt and other psychologists, sociologists, social psychologists, criminologists and philosophers. Chapter One and chapter Two focuse on the concept of aggression and destructiveness and their manifestations in our society, as they are an integral part of it. In addition, culture and aggression constantly interact with each other. Western culture condemns violence, but the question is whether this refusal is sufficiently reflected in all areas of social life, for example when it comes to domestic violence, bullying or potential dangers of the presentation of violence in the media. Chapter Three examines rate of violence and violent crime and the suitability of Czech legislation in terms of its ability to maintain the lowest possible level of these rates. An important finding is that not only law, but also other normative systems and social institutions take part in protecting the society from violence. I also consider the influence of democracy and individualization and...

Doctor of Philosophy / Department of Psychology / Mark A. Barnett / To date, the research testing the predictors of relational aggression has largely mirrored that of the more robust physical aggression literature. Similar to the physical aggression literature, research on relational aggression has focused on age and gender differences and, more recently, the possible associations between relational aggression and other variables. However, there is a lack of research investigating the parent and peer behaviors that could potentially model relationally aggressive behavior in children. The current study drew upon social-cognitive models of aggression to test such associations. Specifically, I measured parents’ use of psychological control with their children, parents’ use of manipulative behavior with their children and other adults, and peer groups’ use of relational aggression to determine whether these variables predicted children’s use of relational aggression. It was expected that the aforementioned variables would be positively associated with children’s use of relational aggression. One hundred and sixty-five fourth-, fifth-, and sixth-grade children (52% male) enrolled in public elementary schools in the Midwest participated in the study. Additionally, 137 female and 70 male caregivers also participated. The children completed questionnaires to measure a) their use of relational aggression, b) their peers’ use of relational and physical aggression, c) the cohesiveness and distinctiveness of their main group of friends, and d) their parents’ use of psychological control. The caregivers also completed questionnaires that assessed a) their behaviors toward other adults when angry, b) how they respond to their children’s misbehavior, and c) social desirability. Consistent with Social Learning Theory and the Social-Cognitive Theory of Aggression, children’s use of relational aggression was positively related to their mothers’ use of psychological control and to their peer groups’ use of relational aggression especially when that peer group was seen as relatively cohesive and distinct. In addition, children’s use of relational aggression was more strongly associated with their parents’ use of psychological control than was their peer groups’ use of relational aggression. The current study was the first to examine and compare the associations between parent- and peer-related variables and children’s use of relational aggression.

Research on the various subtypes of aggression has documented differences in the experience of anger and the expression of angry aggression. Mixed proactive and reactive aggressive individuals exhibit reactive aggression but, unlike reactive aggressive individuals, fail to exhibit angry expressions or physiological arousal. Similar to the proactive group, individuals with psychopathic traits have been found to exhibit emotional underreactivity, and physiological underarousal, while still exhibiting reactive aggression. The present study examined 85 boys (ages 13 to 18) from a detention center. Three groups of aggressive boys were identified via cluster analysis based on the self-report of types of aggressive behavior: a primarily reactive aggressive group (n=29), a mixed reactive and proactive group (n=16), and a low aggressive group (n=40). The three groups were compared on aggressive responding (during a computerized provocation task with low and high provocation trials), on callous and unemotional traits (CU) and on psychophysiological indices of emotional reactivity. All aggressive groups showed greater aggressive responding to high provocation than to low provocation. The mixed aggressive group showed high aggressive responding across all provocation levels, including the no provocation condition, while the reactive aggressive group only showed high levels similar to the mixed aggressive group during low provocation. Unexpectedly, the reactive and mixed aggressive groups reported higher levels of CU traits than the other group. Although the groups did not differ on psychophysiological activity/reactivity, higher levels of CU traits were related to lower skin conductance responses to provocation. Thus, the contribution of high and low CU traits in the three groups to psychophysiological activity/reactivity was examined. Interestingly, the low and mixed aggressive groups who were high on CU traits had lower sympathetic arousal (indexed by skin conductance) and lower sympathetic reactivity to provocation. Thus, the mixed aggressive group showed a general disconnect between their angry aggression (on the provocation task) and their sympathetic reactivity to provocation. However, this was true only if they also showed high rates of CU traits. These results suggest that interventions targeted toward individuals who exhibit particular subtypes of aggression may be more beneficial if the presence of CU traits is also considered.

The purpose of this study was to examine the potential moderating effects of CU traits on the relationship between self-reported social intelligence and aggression in a community sample of boys and girls (ages 14-18). Four subtypes of aggression were measured: reactive overt, reactive relational, proactive overt, and proactive relational. Results indicated that there was not a significant association between social intelligence and any of the aggression subtypes. Neither CU traits nor empathy moderated the association between social intelligence and any of the four subtypes of aggression. Supplementary analyses were conducted to investigate whether level and type of aggression was related to levels of social intelligence and CU traits (or an interaction between the two). Results indicated that at high levels of CU traits, youth exhibited significantly higher levels of proactive overt and reactive overt aggression (t(113.06) than at low levels of CU traits.

The purpose of this study was to qualitatively explore the issues of race and mattering in relation to African American participation within historically White fraternities. Participant perspectives were obtained through six interviews with African American males at four collegial institutions within the Southeastern Region of the United States. Critical Race Theory was utilized to framed issues surrounding race in a homogenous Greek context. A second lens, Rosenberg and McCullough's (1981) concept of mattering, provided a comprehensive description of participants' feelings of significance within the inter-racial Greek experience. Thematic findings indicate that although African American members are recruited to be a part of a particular historically White fraternity's brotherhood, they initially experience marginality. Through continued interaction, the fraternal bonds become strengthened with participants rising to varying levels of leadership within the group, and, mattering to their White fraternal brothers. Other themes related to African American participation within historically White fraternities include: (a) One or no family member that attended college, (b) no immediate family members that are Greek, (c) significance of race is downplayed, (d) limited fraternal knowledge prior to entering college, (e) recruitment is driven by image, status, and counter assumption, (f) stereotypical organizations are racial holdouts; and, (g) discord exist with other African Americans that disapprove of the inter-racial experience.

Research shows that parental psychological control is associated with youth aggression in peer relationships. This includes various aggression roles (aggression and victimization), forms (overt and relational), and functions (proactive and reactive). The current study examined the role of two youth individual traits, Machiavellianism and dysregulation, in the association between psychological control and youth aggression. A sample of 142 participants (age M = 15.4, SD = 1.13, 93% male, 82% African-American) were recruited from several juvenile detention facilities in Louisiana. Participants completed a battery of questionnaires, including self-reports of Machiavellianism, dysregulation, aggression, victimization, and parental psychological control. Bootstrap analyses indicated youth Machiavellianism partially mediated the associations between psychological control and the aggression roles, forms, and functions. Youth dysregulation partially mediated the associations between psychological control and the aggression roles and forms. For the aggression functions, dysregulation partially mediated the association between psychological control and reactive aggression, and fully mediated the association between psychological control and proactive aggression. Regression analyses indicated psychological control and dysregulation were more strongly associated with reactive aggression than proactive aggression. Findings demonstrate the importance of the youth individual traits, Machiavellianism and dysregulation, in explaining the association between psychological control and youth aggression problems. These findings have implications for youth interventions, in that these individual traits may be useful targets to help decrease bullying and aggressive behaviors in peer relationships.

Circadian rhythms are ubiquitous among organisms, influencing a wide array of physiological processes and behaviors including aggression. While many neurophysiological mechanisms are involved in the regulation of aggressive behaviors, relatively few studies have investigated the underlying components involved in the interplay between circadian rhythms and aggression. Spiders are an ideal model system for studying circadian regulation of aggression as they are ecologically both predators and prey. Recent studies have revealed a nocturnal orb- weaving spider Larinioides cornutus exhibits a diel and circadian rhythm in anti-predator behavior (i.e. boldness) that can be manipulated by administration of octopamine (OA) and serotonin (5- HT). Dosing of OA increases boldness of an individual while 5-HT decreases boldness levels. Thus, it appears the serotonergic and octopaminergic system are playing a key role in the daily fluctuations of boldness. This study took a holistic approach to investigate OA and 5-HT levels of head tissue and hemolymph (i.e. blood) as well as the genes involved in synthesis, signaling, and degradation of these monoamines throughout the day (0100, 0700, 1300, and 1900 hours) using HPLC-ED and RNA-sequencing. Although endogenous and circulating levels of OA did not significantly fluctuate, putative transcripts involved in synthesis and signaling did increase in relative expression levels at dusk when L. cornutus begins to actively forage for prey. Endogenous and circulating levels of 5-HT also did not significantly change at the four different time points, but clear patterns of upregulation of 5-HT synthesis enzymes as well as some receptor transcripts were upregulated during the day when L. cornutus would be mostly inactive in its retreat. Lastly, monoamine oxidase, a major catabolic enzyme of monoamines in vertebrates and some invertebrates, was identified in L. cornutus and exhibited substrate specificity for OA compared to 5-HT. Together with the higher enzymatic activity at mid-day compared to dusk, MAO appears to be playing a significant role in regulating the OA and 5-HT signaling in L. cornutus. In conclusion, these results allow a unique preliminary perspective on how OA and 5-HT are influencing the diel shifts in aggression-related behaviors in an ecologically dynamic arthropod.

Aggression ist ein facettenreiches Phänomen, das sowohl in Vertebraten als auch in Invertebraten auftritt. Trotz der weiten Verbreitung dieses Verhaltens sind die neuronalen Netzwerke, die der Aggression zugrunde liegen, noch kaum bekannt. Zahlreiche Studien weisen den biogenen Aminen eine prominente Rolle in der Modulation von Aggression zu. Das Ziel dieser Doktorarbeit war mit Hilfe des Modellorganismus Drosophila melanogaster zu der Aufschlüsselung der neuronalen Korrelate von Aggression beizutragen, insbesondere im Hinblick auf das biogene Amin Oktopamin. In Drosophila sind aggressive Interaktionen aus einer Vielzahl von offensiven und defensiven Verhaltensweisen zusammengesetzt, von denen einige bezüglich der Häufigkeit ihres Auftretens geschlechtsspezifisch sind. Um die Auswertung dieser vielseitigen Verhaltensweisen zu vereinfachen, wurde die Analyse auf einen einzigen Indikator für Aggression beschränkt: den „lunge“. Diese bemerkenswerte Verhaltensweise tritt nur im Kontext der Aggression auf und ist charakteristisch für Männchen. In Kooperation mit Andreas Eckart habe ich ein Computerprogramm entwickelt, das eine automatische Auszählung der lunges in einem vom Forscher gewählten Zeitraum durchführt. Zusätzlich erhält man u.a. Informationen über die Laufstrecke der einzelnen Tiere wie auch über ihre Größe. Dank eines weiteren von uns entwickelten Programms ist es möglich, Kämpfe zweier Drosophila Männchen unabhängig von deren Genotyp wahlweise automatisch oder halb-automatisch auszuwerten. Mit Hilfe dieser Programme wurde gezeigt, dass (1) die gemeinsame Laufaktivität der beiden Männchen mit der Anzahl aller aufgetretenen lunges korreliert und, dass (2) ein Größenunterschied von 8% ausreichend ist, um zu beeinflussen, welches Tier mehr lunges durchführt. Ebenfalls konnte festgestellt werden, dass (3) eine Nullmutation im ‚white’ Gen, welches einen ABC-Transporter kodiert, aggressives Verhalten fast vollständig unterdrückt, was teilweise auf eine visuelle Beeinträchtigung zurückzuführen ist. Außerdem führt (4) das Absenken des White-Levels in verschiedenen Bereichen des Zentralgehirns zu reduzierter Aggression; ein Effekt, der auch durch die chemische Entfernung der Pilzkörper, einer Struktur des zentralen Gehirns, hervorgerufen werden kann. Dies weist darauf hin, dass die Integrität verschiedener neuronaler Netzwerke/Gehirnbereiche erforderlich ist, um wildtypische Aggression zu ermöglichen. Zusätzlich konnte (5) anhand von Mutationen in zwei Genen der Oktopaminsynthese, die beide die Oktopamin-Konzentration zwar erniedrigen, die Tyramin-Konzentration jedoch heben bzw. senken, demonstriert werden, dass Oktopaminmangel Aggression fast vollständig zum Erliegen bringt. Wird ein lunge durchgeführt, so ist dessen Ausführung fast wildtypisch. Rettungsversuche, in denen Oktopamin- und/oder Tyramin-Konzentrationen wiederhergestellt werden, legen nahe, dass ein sehr spezifisches Muster von Oktopamin räumlich und zeitlich gewährleistet sein muss, um ein so komplexes und faszinierendes Verhalten wie die Aggression in Drosophila hervorzurufen. / Aggression is a strikingly multi-faceted phenomenon occurring in vertebrates as well as in invertebrates. Despite its omnipresence, the neuronal basis of aggressive behaviours is yet barely understood. Many studies however, imply a role for biogenic amines in aggression. This PhD project aimed at contributing to the understanding of the neuronal correlates of aggression, with a main focus on the biogenic amine octopamine, using Drosophila melanogaster as the model system. In Drosophila, agonistic encounters of males and females are composed of a variety of both offensive and defensive components, some of which are displayed more often in one sex than in the other. To simplify analysis and to standardize evaluation, I chose to focus on a single indicator of aggression: the lunge, a striking feature unique to Drosophila male aggression. By evaluating the lunge I developed in cooperation with Andreas Eckart for the first time an automated, video-based analysis of Drosophila male aggression. The present software program gives the number of lunges for each fly in a certain time interval. In addition, it provides information such as the distance the fly walked and his size among others. In combination with a second software program that we developed, aggressive interactions between two male Drosophila melanogaster of a genotype of choice can now be registered either completely automatically or if preferred semi-automatically. Using these softwares, I demonstrate that (1) body size differences of 8% and higher influence the outcome of a fight in favour of the larger male; (2) walking activity alters lunge frequency with more lunges performed by more active pairs of males; (3) flies mutant for the white gene, one member of the ABC transporter family in Drosophila, are profoundly impaired in aggression, an effect that is partially due to reduced visual performance. (4) Either knocking-down white in various brain regions or chemically ablating the mushroom body located in the central brain by deleting its neuroblast precursors diminishes aggression, indicating that integrity of various neural circuits/brain regions is required for wild-type aggression to occur. Furthermore, I show that (5) flies lacking octopamine signalling but having altered tyramine signalling display hardly any lunge. A quantitative high-speed analysis revealed that lunge execution is almost indistinguishable from wild-type males. The results from the experiments in which octopamine levels and/or tyramine levels were restored suggest that an elaborate pattern of octopamine levels in time and space is required to enable flies to express wild-type aggressive behaviour.