Summary of the Dissertation
My dissertation drew on data from an ongoing longitudinal birth cohort study of 501 families living in the greater Toronto, Ontario, region. Central to my dissertation is the concept of developmental cascades, in which competencies in one domain of functioning at an early period of development scaffold or build competencies in other domains of functioning at later periods of development. In particular, I was interested in how early social-cognitive skill development at 18 months (empathy, cooperation, joint attention and self-recognition) laid the groundwork for more sophisticated cognitive skills at age 4.5, namely theory of mind (ToM) and executive functioning (EF). I showed that these early social-cognitive competencies predicted later ToM and EF and that these effects were mediated by children’s emergent language skills at age three. Moreover, these effects operated similarly for children from high and low social risk backgrounds, despite overall compromised development in high risk children. These results suggest that high risk children who experience relatively poorer early social-cognitive skill development may be set up to experience continued neurocognitive difficulties in other domains of functioning over the first five years of life.
My dissertation also explored the role of various biomedical and genetic factors in children’s ToM and EF. In the biomedical sphere, I showed that lower birth weight and exposure to maternal pregnancy hypertension were risk factors for deficits in ToM and EF at age 4.5, effects that were again mediated through children’s language. Optimistically, these effects were moderated by responsive parenting at 18 months, such that children facing biomedical risk but receiving high levels of responsive caregiving achieved levels of cognitive functioning comparable to their low risk peers. Finally, in the genetics domain I examined the effects of variability in the oxytocin and vasopressin hormone genes, showing that both of these neurohypophysial systems are operative in children’s ToM and EF development. Interestingly, these genetic effects were contingent upon both environmental (maternal responsiveness) and biomedical (birth weight) factors, suggesting that such genetic effects are non-deterministic and potentially modifiable. Overall, these results highlight the complex biopsychosocial mechanisms underpinning children’s early ToM and EF development, which has implications for children’s downstream academic functioning, social competence and mental health.
How did you come up with the idea for your dissertation research?
As a student in clinical psychology, I was interested in better understanding the mechanisms contributing to children’s neurodevelopment and psychopathology. Over the last decade or so, ToM and EF have become important candidates in the search for endophenotypes underlying liability to several forms of psychopathology. This made me interested in understanding the developmental mechanisms that contribute to ToM and EF development, with the intention of uncovering the social-environmental conditions that either promote or encumber ToM and EF development. Given that ToM and EF are implicated in several other domains of functioning, the idea was that identifying and enhancing these early experiences may protect children against developing problems in other domains of adaptation.
How did you fund your dissertation research?
My dissertation research was funded by several internal and external sources, including a Canadian Institutes of Health Research (CIHR) Doctoral Award, Ontario Graduate Scholarship and APF–COGDOPopens in new window Graduate Research Scholarship. My supervisor, Jenny Jenkins, PhD, also provided support and was the one to whom the large CIHR grant for the longitudinal study was awarded.
What advice would you give graduate students who are proposing or working on their dissertation research?
Make sure you are genuinely interested in your topic area and that you negotiate this with your supervisor. It’s easy to defer to one’s supervisor or be given a particular theme to research, but over time this may become daunting and uninteresting. It is well worth it to take the time to figure out what you are interested in and how this can be carried out within the lab. This will sustain your curiosity and enthusiasm throughout graduate school. Also talk to a lot of other students and faculty and really get to know their work. Some of the most interesting ideas I ever had were by listening to people whom I never thought I’d have anything in common with. Don’t be afraid to think outside the box and integrate concepts from different fields. Finally, have patience with the process. It can be overwhelming and at times unnerving, but most things worthwhile are, to one degree or another. Surround yourself with people who won’t only commiserate with you but with people who will keep you intellectually curious and push around your intuitions. Whether you end up in an academic position or not, graduate school is often a place where you learn not only what to think but how to think. It’s an invaluable experience, regardless of outcome.
What are you working on now?
I’m currently a Banting Postdoctoral Fellow at Harvard Medical School and Boston Children’s Hospital, working on the Bucharest Early Intervention Project with Charles Nelson, PhD. Here, we are looking at the long-term consequences of institutionalization on children’s brain and behavioral development, with a particular focus on psychopathology. This project has tracked children from infancy to age 16, which is an important period of social and biological change. We hope to better understand how early psychosocial deprivation contributes to psychopathology through influences on the brain and cognition and how early enrichment in the form of early foster care might mitigate these risks. I’m excited to be part of such an innovative study and am hopeful that we might one day understand how best to support the health and development of this vulnerable group.