Escalating rates of aggression in South African schools, particularly in the Western Cape, are disconcerting. The early childhood through adolescent years is therefore an important platform for investigations to inform strategies to reduce and prevent aggressive behaviour. Studies conducted outside of South Africa have identified numerous correlates of aggressive behaviour; investigation in South Africa has, however, been sparse. The role of empathy, in specific, has been limited to one prior investigation. Furthermore, while empathy is considered an important construct in explanations of aggressive behaviour internationally, theoretical and methodological issues have undermined findings to date. Our understanding of the relationship between empathy and aggressive behaviour needs refining. I investigated the role of empathy, while simultaneously investigating the role of several known correlates of empathy and aggressive behaviour in typically developing young adolescents (N = 160, ages 11-13; Study 1) and children (N = 76, ages 6-8; Study 2) living in the Western Cape of South Africa. To improve on previous investigations, I employed a framework informed by both neurobiological and behavioural approaches. I conceptualised empathy as comprising affective and cognitive components, as well as a self-regulation component concerned with regulation of affective states. Employing a contextual approach, I argued that the interaction between these empathy components along with multiple contextual factors would provide a more nuanced understanding of the relationship between empathy and aggressive behaviour. I used hierarchical regression and structural equation models to investigate the correlates of aggressive behaviour. Empathy was significantly correlated with Aggressive Behaviour in young adolescents, but not in children. Furthermore, as expected, contextual factors were also significantly correlated with Aggressive Behaviour: Household Income, Parenting Style, and Parent Empathy were correlated with Aggressive Behaviour in young adolescents, while among the measures taken only Parenting Style was correlated with Aggressive Behaviour in children. Future investigations should, as in the current dissertation, work towards articulating the complex web of relationships between correlates of aggressive behaviour and their changes across development.

Social-communication impairments in autism spectrum disorder (ASD) are often ascribed to deficits in empathy. I argue that social-communicative deficits in ASD stem from impairments in specific aspects of empathy, rather than a general empathy impairment. Empathy is defined as the sharing of another's emotion (affective empathy), understanding others' mental states (cognitive empathy), and regulation of one's own emotional state (self-regulation). Empathy can also lead to muscle mimicry and empathic concern for another's wellbeing. I argue that empathy should be measured on multiple levels: cognitive, subjective and physiological. Particularly, measurement of autonomic regulation can contribute to characterising the empathy profile in ASD. Furthermore, confounding factors such as lack of understanding of one's own emotions, or alexithymia, must be accounted for when measuring empathy. I measured subjective trait empathy ratings in people with varying levels of autism traits (N₁ = 519 & N₂ = 98, ages 14 - 45). I also investigated the association between physiological arousal, trait empathy, and empathic concern for (1) sensory pain and (2) facial pain expressions, controlling for alexithymia (N = 98); and examined the evidence for atypical autonomic arousal at rest and during empathy-induction in individuals with ASD. Autism traits were negatively correlated with cognitive empathy and self-regulation, but were not associated with atypical affective empathy per se. However, individuals with poor self-regulation showed heightened subjective affective states, whereas alexithymic individuals showed reduced affective empathy to facial pain expressions. Regarding the autonomic regulation of empathy, there was a significant association between autonomic arousal and affect regulation: Low sympathetic arousal and concurrent high parasympathetic arousal at rest predicted smaller changes in personal distress during pain observation than did autonomic co-inhibition. However, resting state arousal did not predict absolute affective state levels or dispositional empathy, and was not associated with amount of autism traits. In conclusion, the findings do not support the hypothesis of global empathy deficits in ASD. The results suggest that interventions focusing on own-emotion identification and self-regulation skills are important, but caution against the over-hasty adoption of interventions targeting resting state autonomic arousal, which was not related to either ASD or dispositional empathy.

Working memory is involved in a variety of cognitive tasks, with working memory capacity predicting an individual's ability to process information and focus attention on taskrelated information. Subsequently, recent research has investigated whether working memory capacity can be improved through training and whether improvements generalise to other cognitive, behavioural or emotional domains. This training is typically adaptive in nature, changing in difficulty according to participant ability, and can be completed in the participant's home on a computer, giving it the potential to be an easily accessible intervention for a range of clinical populations. The first paper presents a systematic review evaluating the effectiveness of computerised working memory training for individuals with neurodevelopmental disorders, which are often associated with working memory difficulties. The review found that to date, working memory training has been investigated in four neurodevelopmental disorders: attention deficit/hyperactivity disorder; autism spectrum disorder; intellectual disability and specific learning disorder. The findings indicate that although training appears to produce short-term improvements in the working memory capacity, this does not reliably generalise to other cognitive processes or disorder-specific symptoms. The second paper presents a randomised controlled trial investigating the effects of working memory training for reducing worry in high-worriers. Working memory capacity limitations, and subsequent difficulties in attentional control, are believed to be central to the maintenance of worry. Participants were randomly assigned to complete 15 days of nonadaptive working memory training using a 1-back task, or adaptive working memory training using a n-back task. Training led to improvements in working memory capacity and worry symptoms post-training and at four-week follow-up, with improvements on the adaptive training task significantly correlating with improvements in working memory capacity and worry. These findings are discussed in terms of implications for clinical practice and future research, together with the limitations of the study.