In this research cluster we examine the interplay between nature and nurture. Our studies involve genes related to systems such as the dopamine, serotonin, and oxytocin systems, and have a special focus on the differential susceptibility of children and parents to environmental influences.
A series of molecular genetic studies on dopamine-related genes suggested vulnerability of children with the DRD4-7R allele to adverse environmental influences, such as increased levels of externalising behaviour problems and disorganized attachment for children with the DRD4-7R allele and environmental risk. However, these children were not only vulnerable to environmental risk, they also showed remarkably positive outcomes when they received supportive care.
Our results suggest that the supposed vulnerability of carriers of this specific allele is only part of the story: Dopamine-related genes may also be considered as genetic markers of differential susceptibility or biological plasticity in response to environmental influences, for better and for worse.
Our intervention studies using the VIPP-SD provided support for this idea: intervention effects were largest for children with the DRD4 7-R allele, both in terms of decreased externalizing behavior and in terms of lower daily cortisol levels. Interestingly, the story for parents seems to unfold along the same lines, showing genetic differential susceptibility to environmental factors.
One of the current research projects concerns methylation: the effects of the environment on gene expression. Methylation may serve as the interface between the environment and the individual’s genome steering development and behavior. As a consequence, child development might be conceptualized as experiences becoming sculpted in the organism’s DNA through methylation, one of the major epigenetic mechanisms of change.