PhD Oral Exam - Elizabeth Leong, 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

The three studies in this dissertation examined how various socioeconomic (e.g., income-to-needs, maternal education) and psychosocial (e.g., maternal depression, parenting stress) risk factors, as well as situational demands affect the ways in which mothers and their children mutually co-regulate the emotional and behavioural contents of their interactions. Unlike popular approaches, which have captured co-regulation by observing separate mother and child behaviours, a systematic observational coding system was applied to capture co-regulation at the dyadic level.

Study 1 observed depressed and nondepressed mothers and their four-month-old infants (n = 40). Co-regulation and mother-infant relationship quality were coded during the normal and reunion periods of the Still-Face (SF) and Separation procedures (SP). Results showcase the importance of considering social contextual demands when examining co-regulatory and relationship differences in depressed mothers and their infants (e.g., depressed dyads engaged in more one-sided co-regulation, but only after experiencing a perturbation).

Study 2 examined co-regulation in a sample of mother-child dyads (n = 144) during early childhood with mothers who had histories of disadvantage. Co-regulation was observationally coded during three different interaction periods, which varied in demandingness. Broad dimensions of socioeconomic (e.g., low income-to-needs) and psychosocial (e.g., parent stress) risk were created using confirmatory factor analysis. Latent profile analysis was used to establish co-occurring changes in co-regulatory patterns across interaction periods. Results indicated that dyads who had less co-regulatory flexibility across interaction periods had higher levels of psychosocial risk and suboptimal relationship quality.

Study 3 focused on the longitudinal implications of the socioeconomic and psychosocial risk dimensions, as well as the co-regulatory profiles created in Study 2 for the development of child internalizing and externalizing problems. The 144 dyads included in Study 2 participated in additional testing, during middle childhood (n = 110) and during late childhood/early adolescence (n = 93). Using growth curve analysis, psychosocial risk was found to predict internalizing problems.

These studies make important contributions by clarifying how various risk factors shape co-regulation and socioemotional development during important developmental periods. In addition, by examining various interaction contexts, we identify in which types of contexts various risk factors exert a greater influence on co-regulation.