Genomic rearrangements, particularly deletions and duplications, are known to cause many genetic disorders. The chromosome 7q11.23 region in humans is prone to recurrent chromosomal rearrangement, due to the presence of low copy repeats that promote non-allelic homologous recombination. The most well characterized rearrangement of 7q11.23 is a hemizygous 1.5 million base pair (Mb) deletion spanning more than 25 genes. This deletion causes Williams-Beuren Syndrome (WBS; OMIM 194050), a multisystem developmental disorder with distinctive physical and behavioural features. Other rearrangements of the region lead to phenotypes distinct from that of WBS. Here we describe the first individual identified with duplication of the same 1.5 Mb region, resulting in severe impairment of expressive language, in striking contrast to people with WBS who have relatively well preserved language skills. We also describe the identification of a new gene for a severe form of childhood epilepsy through the analysis of individuals with deletions on chromosome 7 that extend beyond the boundaries typical for WBS. This gene, MAGI2, is part of the large protein scaffold at the post-synaptic membrane and provides a new avenue of research into both the molecular basis of infantile spasms and the development of effective therapies. Individuals with smaller than typical deletions of 7q11.23 have delineated a minimal critical region for WBS and have implicated two members of the TFII-I transcription factor family. To better understand the contribution of these genes to WBS, I have generated animal models with these genes deleted singly and in combination. Disruption of the first gene, Gtf2ird1, resulted in phenotypes reminiscent of WBS including alterations in social behaviour, natural fear response and anxiety. An alteration in serotonin function was identified in the frontal cortex and may be linked to these behavioural phenotypes. Together with a model for the second gene, Gtf2i, and the double deletion model that was generated using Cre-loxP technology, these resources will permit the study of the individual and additive effects of hemizygosity for Gtf2i and Gtf2ird1 and will greatly expand our understanding of the role the TFII-I gene family in WBS.

Weakly electric fish produce and detect electric fields and use their electrosensory modality in a number of behaviours including navigation and communication. They can modulate their electric discharge in frequency and amplitude to produce electrocommunication signals in variable patterns during social interactions. In one model neuroethological species, Apteronotus leptorhynchus, the most commonly produced communication signal is the ‘small chirp’ – a brief 10-30ms modulation. Individuals tend to produce these signals at high rates during agonistic interactions. In this thesis I will explore the social value of chirps, and to a lesser extent other communication behaviours, in A. leptorhynchus using a variety of experimental designs involving different staged social contexts. I use time series analysis methods to explore the patterns of chirps produced and accompanying aggressive behaviours. I first characterize electrocommunication and chirping in pairs of free swimming fish and correlate signal production with aggressive displays. Bursts of echoed, or reciprocated, chirps tend to be produced in the intervals separating aggressive attacks. Behavioural analysis shows that fish respond to conspecific chirps with echoed chirps and decreased aggression in social contexts outside the range in which previous modelling and electrophysiological data predicted that chirps could be encoded effectively. I then characterize the chirping and aggressive responses to playbacks simulating intruders with different chirping styles to test whether alternative chirp patterns differentially influence conspecific behaviour. In response to simulated intruders producing chirps that echo the real fish’s chirps with a short latency, less aggressive fish tend to produce more of their chirps in bursts than more aggressive fish. For randomly chirping intruders, the response of fish depends on the rate of chirps delivered. Fish respond less aggressively, with fewer chirps, and echo the stimulus chirps at a higher rate when high rates of random chirps are delivered than when responding to simulated intruders with low rates of randomly delivered chirps. Further, across all playback scenarios, fish that produce chirps in response to the playbacks are more aggressive than those that do not chirp. Finally, to better understand the electrosensory inputs during these interactions, I characterize changes in the electric image received by a restrained fish during movements of a free-swimming conspecific and correlate these with chirp production. When one fish is restrained, bursts of chirps tend to be associated with approach behaviours. Communication signals often function to promote individual assessment of potential rivals during agonistic encounters and bursty, antiphonal chirp exchanges may facilitate these assessments and deter potentially costly physical escalations.

Researchers have raised concerns about measurement equivalence in comparing personalities across cultures using personality assessments. The self-reported personality measurements often do not assess the same construct, trigger different response styles (i.e., extreme response style), or use behavioral exemplars that are inappropriate across cultures (Byrne&Watkins, 2003; Chen, 2008; Poortinga, van de Vijber,&van Hermert, 2002, van de Vijver&Leung, 1997). James et al. (2005) developed a new measurement system for aggression that is different from traditional personality assessment. It is referred to as the Conditional Reasoning Test for Aggression (CRT-A). The CRT-A is an indirect measure for assessing unconscious motives to be aggressive that was developed in the USA. It has not been studied with people from different cultures. Study 1 investigated the equivalences of the Aggression Questionnaire (AQ) and the CRT-A by administering both to groups of Americans (n=432) and Koreans (n=363). Results based on the exploratory and confirmatory factor analyses and DIF analyses showed that the AQ and CRT-A are not invariant across these cultures. Study 2 replicated LeBreton et al.(2007) study regarding faking issues of the CRT-A with the Korean population. Study 2 found that on the CRT-A, Koreans were able to identify aggressive alternatives when they were told to do so, and Korean students and employees did not score differently on the CRT-A. Implications and future directions of the study are discussed herein.

This study estimated the association between aggressive behavior and two different types of emotion regulation, one operating on the conscious level with voluntary effort (i.e., suppression) and the other operating on the unconscious level with involuntary effort, or automatically (i.e., repression). Results from a correlation analysis among self-assessed suppression and repression and other-rated aggressive behavior showed that repression is more significantly linked to aggressive behavior than suppression. Further investigation using physiological and neural assessments was performed to determine the critical properties, including cardiac reactivity and neural substrates, of repression related to aggressive behavior. Based on the findings from multiple approaches in assessment, this study suggests that unconscious emotion change inferred from self-assessed repression (in Study 1) and neural activity (in Study 2) more significantly predicts aggressive behavior than personality. Implications for both aggression and emotion research are discussed along with the measurement equivalence issue.

Following social defeat, male hamsters exhibit behavioral changes characterized by a breakdown of normal territorial aggression and an increase in submissive/defensive behaviors in the presence of a non-aggressive intruder (NAI). We have termed this phenomenon conditioned defeat (CD). By contrast, only a small subset of defeated females exhibit submissive/defensive behavior in the presence of a NAI. We hypothesized that fluctuations in gonadal hormones might contribute to differences in the display of submissive behavior in intact female hamsters. Following social defeat, proestrous females (higher endogenous estradiol) were more likely to display conditioned defeat compared with diestrous 1 (lower endogenous estradiol) females. This finding suggests that there is an estrous cycle-dependent fluctuation in the display of CD in female hamsters and suggests that increased estradiol might contribute to increased submissive behavior. We then demonstrated that ovariectomized females given estradiol prior to CD testing exhibited significantly higher submissive behavior in the presence of a NAI suggesting that estradiol increases the expression of CD in female hamsters. We have also shown that castrated males that were singly housed for four weeks displayed significantly more submissive behavior than did their intact counterparts. Interestingly, castrated and intact males that were singly housed for 10 days prior to behavioral testing displayed similar behavior during CD testing. Together these data suggest that androgens and isolation modulate the display of CD in male hamsters. Finally, we examined brain activation following CD testing in defeated males and females (in diestrus 1 and proestrus). Defeated male and proestrous females exhibited increased Fos activation in the dorsal lateral septum and hypothalamic paraventricular nucleus relative to defeated diestrous 1 females. Diestrous 1 females exhibited increased Fos expression in the lateral bed nucleus of the stria terminalis compared with both defeated groups. Collectively, these data suggest that gonadal hormones and duration of individual housing modulate the display of CD in female and male hamsters and that those animals which display CD exhibit differences in patterns of neuronal activation than do those that do not display CD.

Research suggests that playing violent video games increases the likelihood of aggression. However, less clear is how individual characteristics influence the mechanisms that lead to aggression. Using Anderson and Bushman’s (2002) General Aggression Model as a framework, the present study examined the independent and joint effects of individual differences and situational factors on affective and physiological reactivity to playing a violent video game. One hundred thirty-three participants completed self-report measures of trait aggression and violent video game exposure. They were randomly assigned to groups instructed to play a video game using either violent or nonviolent strategies while facial electromyography, heart rate, and electrodermal activity were measured. Positive and negative affect was assessed via self-report prior to and following video game play. It was hypothesized that trait aggression and level of past exposure to violent video games would be positively related to increases in physiological arousal and negative affect among participants in a violent, relative to a nonviolent, condition. Hierarchical regression analyses failed to detect a significant relationship between trait aggression and changes in heart rate, facial electromyography, or self-reported affect as a function of game condition. However, significant positive relationships were found between trait aggression and skin conductance, but only in the nonviolent condition. Analyses revealed that past exposure to violent video games was positively related to increased skin conductance among participants in the non-violent, but not the violent video game condition. Past exposure to violent video games was also positively related to increased heart rate, but this was among participants in the violent, but not the non-violent condition. Significant relationships between past exposure to violent video games and changes in facial electromyography and self-reported affect as a function of video game condition were not found. Findings are discussed in terms of how trait aggression and past exposure to violent video games influence arousal, and potentially, the likelihood of aggressive behavior.

This study provided the first direct test of the cognitive underpinnings of the attention-allocation model and attempted to replicate and extend past behavioral findings for this model as an explanation for alcohol-related aggression. Men were randomly assigned to a beverage (Alcohol, No-Alcohol Control) and a distraction (Moderate Distraction, No Distraction) condition. All men were provoked by a male confederate and completed a dot probe task and a laboratory aggression task without distraction or while presented with a moderate distraction task. Results indicated that intoxicated men whose attention was distracted displayed significantly lower levels of aggression bias and enacted significantly less physical aggression than intoxicated men whose attention was not distracted. However, aggression bias did not account for the lower levels of alcohol-related aggression in the distraction, relative to the no-distraction, condition. Discussion focused on how these data inform intervention programming for alcohol-related aggression.

Sedan 1990-talet har behandlingsmetoden Aggression Replacement Training (ART) fått ett stort genomslag i Sverige och metoden används såväl inom socialtjänstens öppenvård som inom kriminalvården, samt på många av Statens institutioners ungdomshem. ART tycks idag vara en av de mest spridda manualbaserade behandlingsmetoderna (Kaunitz & Strandberg, 2009, s. 37). Mot bakgrund av metodens omfattande tillämpning inom dessa områden, ansåg vi att det fanns skäl till att undersöka hur ungdomar som genomgått ART träning upplevde metoden. Detta är också syftet med denna studie. Då vi har förstått att det finns få svenska kvalitativa studier om ungdomars erfarenheter av ART, menar vi att det är av intresse att i föreliggande studie belysa denna fråga.Vi valde därför att genomföra en kvalitativ undersökning, varvid vi intervjuade sex stycken ungdomar som samtliga har haft problem med ett antisocialt beteende och kriminalitet. I syfte att analysera vår empiri har vi utkristalliserat följande fem teman: motivation, gruppens betydelse, användbara kunskaper, övning ger färdighet och faktorer som påverkar. Vår studie visar bland annat att ungdomarnas aggressiva och destruktiva beteende genom åren har belönats och förstärkts, vilket vi anser kan vara en förklaring till varför dessa beteenden hos ungdomarna har vidmakthållits. Vi har också sett att ungdomarnas motivation till att förändra sina destruktiva beteenden tycks vara avgörande för att ungdomarna skall vilja ta till sig de verktyg som ART tillhandahåller. Vidare kan vi konstatera att ART gruppens sammansättning och atmosfären i gruppen är viktig för att ART deltagarna skall kunna ge sig hän i träningen, och därmed få en större behållning av behandlingsmetoden. Vi har förstått att de kunskaper som ungdomarna har förvärvat genom ART, riskerar att försvinna då missbruk finns med i bilden. Då den unge eventuellt har en komplex problematik, anser vi att andra behandlingsprogram utöver, eller i kombination med ART, kan vara verkningsfulla.

The purpose of this study was to examine how school personnel describe and interpret the phenomenon bullying among girls, and also what their interpretations are based upon. More specifically its aim was to find out what characterizes and causes girl-to-girl bullying, according to school welfare officers and teachers. We wanted to find out how school personnel look upon aggression among girls and social expectations on girls behavior. The analysis was based on two kinds of perspectives: one focusing on gender and one focusing on power in relationships. Research shows that girl-to-girl bullying is hard to observe and that this problem has been invisible in earlier studies. We thought that this phenomenon needs to be brought up and that is one of the reasons why we wanted to examine this subject. This study was based on qualitative interviews with school welfare officers and teachers. A main theme in our study is that our respondents describe girl-to-girl bullying as subtle and quiet. We also found that some of our respondents disagreed on this statement. Their opinions were mainly based on their own experience from working in a school environment. As a conclusion we found out that factors such as social maturity and gender roles can be used as explanations on the phenomenon girl-to-girl bullying. We found out that our tools, power and gender theories, could not fully explain why girls bully in a certain way and how school personnel interpret the phenomenon. More knowledge is needed to understand more about girl-to-girl bullying.

Past models (i.e., Crick and Dodge, 1994) of children’s social information processing (SIP) have neglected to include the role of emotions in children’s reasoning during social situations. A recent reformulation (Lemerise and Arsenio, 2000) updated Crick and Dodge’s model to incorporate emotions and their impact on children’s processing. Since then, studies have examined the influence of emotion in children’s SIP, but few have investigated the impact of children’s affective ties with their peers. This study explores the effect of the participant’s relationship with the provocateur on subsequent consequential reasoning concerning possible hostile, passive, and competent response; in addition, it addresses gaps in the literature by utilizing a different age range and investigating the response decision step of SIP. A sample of second and fifth graders (N=101) completed a social cognitive interview in which they reasoned about competent, hostile, and passive responses when the provocateur was a friend, neutral peer, or an enemy. Results indicated multiple relationship effects and gender differences, which illustrated the impact relationships can have on SIP.