Nature affects nurture in adoptive child-parent relationships, researchers find

UNIVERSITY PARK, Pa. — Genetics play a significant role in how children respond to their adoptive families’ parenting style, according to a new study published by a multi-university team of researchers that includes Jenae Neiderhiser, Penn State distinguished professor of psychology and human development and family studies.

The findings, “Parenting in the Context of the Child: Genetic and Social Processes,” published by Monographs of the Society for Research in Child Development. The work is part of the longitudinal Early Growth and Development Study (EGDS), an ongoing prospective adoption study launched by Yale psychiatrist David Reiss, lead author on the current monograph. Its findings could result in practical interventions pertaining to children’s social development and mental health, according to the study authors.

The researchers analyzed data from interviews, surveys and direct observations of 561 children adopted shortly after birth, along with their birth and adoptive parents, all of whom are participating in the EGDS. Supported by the National Institutes of Health and in partnership with 45 adoption agencies in 15 states, the EGDS comprises 561 families recruited between 2000 and 2010, as well as nearly 1,000 more participants recruited after 2013. This study focuses on the original 561 families and how genetics may influence how children respond to parenting styles.

“A huge message from the study is that differential responses to children are appropriate, because not all children need the same thing,” Neiderhiser said. “Parents often think they need to parent all of their children in the same way, but it’s okay to parent your children differently.”

The researchers found that a child’s genetic predisposition can influence not only how the child responds to a parenting style, but also their relationship with their parents. For example, if birth parents are not interested in engaging socially, there may be more hostility between a child who inherited the same lack of interest and their adoptive parents, according to the researchers.

The data also revealed that children with highly assertive temperaments showed more anger, which in turn prompted more parental hostility that increased the likelihood of behavioral problems in the child. However, the researchers said, these issues were less likely if the adoptive parents had a satisfying marriage and exhibited more parental warmth and affection.

According to Neiderhiser, it appears that children’s genetics inform the type of parenting they need to thrive. Children whose birth parents had a broad range of mental health disorders benefited from highly structured parenting; on the flip side, children whose birth parents had little or no evidence of mental health issues but who received more structured parenting demonstrated higher levels of behavior problems.

“Because the birth parents are not parenting the child, we can infer that these effects are due to genes shared between birth parent and child,” Neiderhiser said.

These genes could accelerate or prevent deteriorating child-parent relationships, according to Neiderhiser. For instance, children of depressed birth mothers responded more negatively to adoptive parents’ hostile parenting compared with children of birth mothers with low depressive symptoms. This negativity resulted in the rearing parents experiencing more depressive symptoms and increasing their hostility toward their child. In contrast, children with a more “sunny” inherited disposition had a lower risk of receiving hostile parental responses, especially from fathers.

“Parental response can make a real difference,” Neiderhiser said. “Children will respond in certain ways that are correlated with their genotype, and this response results in a different response from the parent that can produce, unsurprisingly, a circular or reciprocal effect.”

Parental response, Neiderhiser explained, can exacerbate problems in the child and in their relationships that are correlated with the child’s genetic risk, and vice versa. But, if the parents are responding in a way that is the adverse of the child’s risk, then it will help to decrease the expression of that risk in the child. If a child’s birth parent has high levels of depressive symptoms, for example, it’s beneficial if the adoptive parent responds to them in a way that helps to dampen those effects in the child.

“If the child cries or is stressed or anxious, or if the parents respond in a way that supports that child instead of being harsher with the child, then that helps the child to be less likely to express those types of behaviors,” Neiderhiser said.

The researchers also corroborated some existing theories of parenting, such as an environmental effect on children’s behavior. For instance, adoptive parental harshness was associated with increased child aggression from age 27 months to 4.5 years but was most pronounced among fathers and was not detected from children between the ages of 4.5 and 6.

“The findings suggest that targeted interventions, tailored to the unique characteristics of the child, are likely to be most effective and most appropriate,” Neiderhiser said. “Recognizing that children come into the parent-child relationship with things that influence how others treat them, that can help parents create the best environment for their families.”

In addition to Neiderhiser and Reiss, the research team includes Jody M. Ganiban of George Washington University, Leslie D. Leve of the University of Oregon, Daniel S. Shaw of the University of Pittsburgh, and Misaki N. Natsuaki of the University of California, Riverside.