Psychology - Theses, Dissertations, and other Required Graduate Degree Essays

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An investigation of profiles of polysubstance use in homeless & precariously housed individuals

Author: 
Date created: 
2020-07-02
Abstract: 

Despite the prevalence of polysubstance use among homeless and precariously housed persons, the cognitive and functional consequences of substance use patterns are poorly understood. This may be due in part to the limitations of existing work that attempts to isolate substances (e.g. methodologically or statistically) or lacks granularity (e.g. cross-sectional or lacking frequency of use). As such, this study aimed to improve upon past work by evaluating naturally occurring patterns of polysubstance use longitudinally. Using cluster analysis, this study revealed three validated substance use profiles: Frequent Heroin with Moderate Methamphetamine Use, Frequent Cannabis Use, and Infrequent to Moderate Polysubstance Use. Mixed general linear models indicated that the use profiles were not associated with differences in cognitive trajectory or capacity, however, persons engaged in frequent use showed poorer social and occupational functioning compared to a moderate use group. Implications are discussed.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Allen Thornton
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Can collaborative giving boost generosity?

Author: 
Date created: 
2020-07-16
Abstract: 

People often make charitable donations together with others, from strangers to romantic partners. Do people donate more generously when they give collaboratively with others? Past work has been largely correlational, mixed, and limited. To overcome prior empirical shortcomings, I conducted two well-powered, pre-registered experiments to test whether collaborative giving boosts generosity while also exploring its interpersonal and emotional consequences. In Study 1 (N =202; 101 dyads) and Study 2 (N =310; 155 dyads), pairs of unacquainted undergraduate peers earned money for evaluating a charitable advertisement. Then, I randomly assigned pairs to donate either collaboratively (Studies 1-2), individually in the presence of one another (Studies 1-2), or privately (Study 2). In both studies, I observed no differences in generosity across conditions. However, collaborative (vs. individual) giving boosted generosity through greater intrinsic enjoyment. Additionally, collaborative (vs. individual) giving facilitated social bonds between peers. Practical and theoretical insights are discussed.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Lara Aknin
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Agreeableness predicts Theory of Mind in older and younger adults

Author: 
Date created: 
2020-06-11
Abstract: 

Theory of Mind (ToM) reflects the ability to accurately infer others’ mental states. The five factor personality traits, particularly Neuroticism and Agreeableness, have been associated with ToM in previous studies; however, that research failed to control for vocabulary knowledge and only used one measure to assess ToM. We aimed to re-investigate the relationship between personality factors and ToM while controlling for vocabulary knowledge, using a multimethod approach to measure ToM, extending the research to include older adults, and exploring mediators and moderators. In our sample (N = 179; 91 younger adults, 88 older adults), Neuroticism did not have a main effect on ToM. While more Agreeable older adults tended to have better cognitive ToM, more Agreeable younger adults had worse cognitive ToM. Empathy did not mediate the relationship between Agreeableness and cognitive ToM, and anxiety symptoms did not moderate the association between Neuroticism and cognitive ToM. These findings have implications for older adult health and wellbeing.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Alexander Chapman
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Dopamine receptor D4, attachment security and parenting interventions: Examining associations through a meta-analysis and an intervention study

Date created: 
2020-01-20
Abstract: 

Parenting interventions reduce mental health problems in children. Considerable research has explored the psychosocial pathways of treatment effects; however, less is known about the biological mechanisms of intervention outcomes. Thus, the over-arching goal of the current work was to contribute to the literature on the biological influences of parenting-based treatment outcomes, using a candidate gene approach. Through a meta-analysis (Study 1) and intervention study (Study 2) the present work examined the effects of the Dopamine Receptor D4 (DRD4) gene and attachment on a child’s response to parenting-based interventions, with a focus on adolescent samples. Study 1: A meta-analysis and systematic review were performed to provide an overview of the literature. Articles were retrieved from PsycINFO, Medline and Proquest databases, relevant journals, and a manual search. In total, k = 27 articles were obtained, with k = 12 representing unique samples, and data available from k = 10 studies. Articles were coded to obtain effect size data and study characteristics. High inter-rater reliability was achieved. Overall, results replicated previous findings of gene-by-intervention effects. The combined effect size of the intervention in the genetically “susceptible” group was statistically significant and yielded a small effect (d = -0.34), while the “non-genetically susceptible” group’s results were not statistically significant and yielded a negligible effect (d = -0.01). Sub-analyses on the DRD4 gene and attachment-based interventions followed similar patterns. There was a paucity of research on adolescent samples, and thus a qualitative literature review was performed. Study 2: A study on a sub-sample (N = 341) from the provincial evaluation of the Connect Parent Group was performed on the role of DRD4 and attachment on youth outcomes. Demographic information, attachment ratings, and measures of psychopathology were collected from youth self-report at pre-, mid-, post-treatment and at 6 month follow-up. Primary analyses were conducted using structural equation modeling to test a mediated moderation model. Partial support for the hypotheses was observed. This work was one of the first to assess the genetic moderation of parenting-based intervention outcomes in adolescents. Clinical implications for tailoring parenting interventions are discussed.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Marlene Moretti
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) Ph.D.

The comparative impact of different forms of violence exposure in youth on long-term adult outcomes

Author: 
Date created: 
2020-02-27
Abstract: 

Violence exposure during childhood and adolescence is associated with a wide range of negative emotional and behavioural outcomes. Despite an extensive body of research, there are numerous problems with respect to how violence exposure has been operationalized and measured; design and methodology (i.e., cross-sectional or short-term longitudinal studies); limited outcome measures; and overall conflicting findings. Further, there is a paucity of research examining the effects of violence exposure during youth on long-term adult outcomes. Given the considerable individual variability that exists with respect to the effects of violence exposure, longitudinal research is needed to clarify the comparative impact of different types of violence exposure across locations. Using a large and racially diverse community sample (n = 753; male = 58%; Black = 46%), the current longitudinal study aimed to elucidate the comparative and cumulative effect of different types of violence exposure (witnessing versus victimization) across different locations (home, school, neighbourhood) occurring during youth (lifetime through grade 8) on long-term adult (age 25) outcomes of internalizing, externalizing, and attention problems; substance use; and intimate partner violence perpetration. Results indicated that victimization, but not witnessing violence, predicted all five adult outcomes. More specifically, being victimized in the home setting was associated with the widest range of negative outcomes (internalizing, externalizing, and attention problems), while school victimization was specifically associated with substance use problems in adulthood. The nature and severity of direct victimization may put youth at greater risk for developing emotional and behavioural dysregulation, and the home and school settings appear to be important contexts for adolescent development. Additionally, when youth experienced multiple types of violence across multiple locations (cumulative violence exposure), they experienced a broader and more diverse range of negative outcomes in adulthood. This study extended existing research on the effects of violence exposure during childhood and adolescence. Taking a life-course perspective, these findings demonstrate that violence exposure has long-term negative effects evident well into adulthood, with victimization at home and school as more robust predictors of negative adult outcomes than exposure to neighbourhood violence. Based on these findings, preventing and effectively addressing youth victimization, especially at home and school, must be a top research, practice, and policy priority.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Robert McMahon
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) Ph.D.

Risk domains and factors of the Multi-Level Guidelines: An updated examination of their support in the literature

Author: 
Date created: 
2019-12-03
Abstract: 

While the field of violence risk assessment has seen tremendous growth in the area of individually oriented violence, risk assessment for group-based violence (GBV) is still in its infancy. One tool developed specifically for assessing this form of violence is the Multi-Level Guidelines (MLG; Cook, Hart, & Kropp, 2015), which is comprised of 16 risk factors nested into four domains: Individual, Individual-Group, Group, and Group-Societal. Given the rapid pace at which the research on terrorism risk factors, in particular, has developed (Gill, 2015b), this review sought to update the systematic review from which the MLG was developed and examine the extent to which its domains and factors are supported by recent empirical research on GBV. A total of 151 studies were reviewed, spanning several forms of GBV. Overall, the content and structure of the MLG appear to be broadly supported by recent empirical research, although the evidence base for the Individual-Group and Group domains is still relatively small, and the strength of much of this research is limited by methodological constraints. The MLG and the HCR-20 V3 (Douglas, Hart, Webster, & Belfrage, 2013) were then applied to a brief series of case studies of GBV in order to demonstrate the applicability of the MLG to this form of violence, and to compare it to the HCR-20 V3 in this respect. While both tools were found to be broadly applicable, it was clear that the MLG captured specific risk factors that are unique to GBV.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Stephen D. Hart
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

The effects of cross-examination on children’s reports

Author: 
Date created: 
2020-04-23
Abstract: 

Cross-examination is a fundamental aspect of the adversarial legal system; it is meant to test the reliability of the evidence. To date, all research has examined the effect of cross-examination with children who have experienced a unique event. However, many children who testify have experienced multiple similar instances of abuse. In two experiments I investigated the effects of cross-examination on the consistency, accuracy, and perceived credibility of children’s reports. In Experiment 1(N = 222), younger children (kindergarten or grade 1) and older children (grade 3, grade 4, or grade 5) participated in either one (single-event; SE) or five similar (repeated-event; RE) magic shows. One-week later, children received a baseline interview which used best practice techniques. Next, half the children were cross-examined (cross) and the other half answered all cued recall questions again (direct-direct; DD). Finally, all children received a re-direct interview (Interview 3) and were encouraged to answer the questions as they remembered the details occurring during the show. In most analyses children in the cross condition were less accurate during Interview 2 than children in the DD condition. The re-direct interview helped to rehabilitate accuracy for variable details (vary in predictable ways); however, the negative effects of cross endured for accuracy of deviation details (vary in unpredictable ways) and when accuracy was defined broadly. In Experiment 2, recorded interviews of the children were randomly sampled and matched on accuracy. Undergraduate participants (N = 532) rated the children’s perceived honesty, accuracy, credibility, and susceptibility to suggestive questions. Younger children and RE children were perceived as less honest, accurate, and credible than older children and SE children. Children who were cross-examined were rated as less susceptible to suggestive questions than children in the DD condition. These results show that cross-examination has detrimental effects on children’s reports and that RE children may be disadvantaged when testifying in court.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Deborah Connolly
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) Ph.D.

Is depression a risk factor for adolescent offending? A meta-analytic review

Author: 
Date created: 
2020-04-17
Abstract: 

The literature is mixed about whether depression is a risk or protective factor for violence and general offending in adolescents. A meta-analytic review was conducted on 29 studies reporting on 27 unique prospective samples, with a total of 97,316 participants. The majority of samples were community (non-offender) or population samples (77.8%, k = 21), with a smaller proportion being justice-involved (e.g., incarcerated, probation, or history of arrest) samples (22.2%, k = 6). Overall, depression was associated with an increased risk for general offending (OR = 1.58, p < .001), and violent offending (OR = 1.45, p < .001). For community adolescents, depression was a significant risk factor for general offending; however, in justice-involved youth depression was not a significant risk factor. Gender, study quality, publication year, and country of publication did not moderate any of the results.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Jodi Viljoen
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Singlehood and social identity: Does identifying with other singles mitigate the negative effects of perceived discrimination on wellbeing?

Author: 
Date created: 
2019-11-22
Abstract: 

Single people tend to experience lower wellbeing than coupled people. One explanation for this phenomenon is that single people experience discrimination, which can negatively impact psychological wellbeing. Using data across two studies composed of single university students (N = 128) and single people from the community (N = 67), I examined whether identifying strongly with other singles might buffer the adverse effects of discrimination on wellbeing. The results demonstrated some inconsistent effects: greater singlehood commonality mitigated the negative impact of perceived discrimination on wellbeing in a sample of young singletons (Study 1), but exacerbated the negative impact of perceived discrimination on wellbeing in a community sample of singletons (Study 2). These findings hold implications for understanding the potential costs versus benefits of single people’s group identification.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Yuthika Girme
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) M.A.

Adverse childhood experiences in Indigenous and Caucasian female and male youth on probation: Rates and interventions

Author: 
Date created: 
2020-01-17
Abstract: 

Even though Indigenous peoples are overrepresented in the Canadian justice system, little research has studied potential mechanisms for this overrepresentation. To address this gap, the current dissertation examined the association between adverse childhood experiences (ACEs) and recidivism and investigated whether youth probation officers (YPOs) considered trauma in their case formulations. The sample comprised 187 justice-involved Indigenous and Caucasian female and male youth. ACEs, reoffense records, risk statements and trauma focused interventions were coded from justice files with a follow-up period of 1.51 years. Results showed that compared to Caucasian youth, Indigenous youth had significantly higher ACE scores. Indigenous males violently recidivated significantly more than Caucasian males and Indigenous females had significantly more any recidivism than Caucasian females. ACEs predicted and shortened time to any recidivism, added incremental validity above the Structured Assessment of Violence Risk in Youth (SAVRY; Borum, Bartel & Forth, 2006) for any recidivism and mediated the relationship between Indigenous ethnicity and any recidivism. YPOs screened for ACEs but infrequently linked ACEs to recidivism. Finally, trauma focused interventions like therapy referrals were rare for youth with high ACEs. Overall, the current study found that ACEs were especially important for Indigenous youth. As such, screening for ACEs alongside the SAVRY and including Indigenous specific trauma interventions (e.g., Honoring Children interventions) may reduce recidivism for Indigenous youth. Future research should incorporate participatory action approaches and focus on how colonialism plays into justice overrepresentation for Indigenous youth.

Document type: 
Thesis
File(s): 
Supervisor(s): 
Jodi Viljoen
Department: 
Arts & Social Sciences: Department of Psychology
Thesis type: 
(Thesis) Ph.D.