PhD Oral Exam - Mari C. Shanahan Somerville, Psychology

When studying for a doctoral degree (PhD), candidates submit a thesis that provides a critical review of the current state of knowledge of the thesis subject as well as the student’s own contributions to the subject. The distinguishing criterion of doctoral graduate research is a significant and original contribution to knowledge.

Once accepted, the candidate presents the thesis orally. This oral exam is open to the public.

Abstract

Moving from a disadvantaged neighbourhood to one of more affluence has been shown to improve life outcomes. However, not everyone manages to overcome the environmental and social hazards of such neighbourhoods. Success may depend on individual differences such as childhood social behaviour, education, and criminal activity. Crime and neighbourhood disadvantage are highly correlated, but the directional nature of this relationship and its transactional nature throughout life have rarely been examined. Part One of the current investigation examined whether individual characteristics, including childhood social behaviour, education, and criminality, contribute to the perpetuation of socioeconomic immobility across adulthood via neighbourhood disadvantage using a growth curve model. In Part Two, the potential transactional nature of associations between crime and disadvantage over time were examined utilizing a cross-lagged analysis.

Participants were drawn from the Concordia Longitudinal Research Project, a prospective, 47-year longitudinal investigation of over 4000 families from neighbourhoods of low socioeconomic status in Québec, Canada. In Part One, Growth curves modeled differences in change in participants’ neighbourhood disadvantage (via census data) over 30 years, from middle-childhood (age 7-12) to middle-adulthood (age 46-57). Predictors included childhood social behaviours and total criminal charges in early adulthood (age 18-28). In Part Two, to examine potential transactions, cross-lagged associations were modeled between neighbourhood disadvantage across four time points (1976, 1986, 1996, 2006). In this model, childhood neighbourhood disadvantage (1976) and aggression were included as predictors and total years of education was included as a mediator.

Part One results indicated that participants with no criminal charges showed the greatest improvement in neighbourhood over time, whereas those with many charges showed little improvement. Participants with histories of childhood aggression, withdrawal, or lower likeability were also less likely to experience improvements. Results from Part Two indicated that the association between charges and neighbourhood disadvantage was transactional over time and that education may play an important protective role for individuals who grow up in disadvantaged neighbourhoods or for more aggressive children. These findings provide evidence for the importance of criminality in undermining at-risk young adults’ ability to overcome neighbourhood disadvantage, highlighting risk and protective factors that may inform early and long-term intervention and policy.