Is 23% of Parenting Really Due to Children’s Genes?

POSTED BY: PHIL GORDON ON FRI, SEP 27, 2013

I just read an interesting article that warrants some discussion.  I found the article because the press was reporting that a study found 23% of parenting was attributable to the child’s genetics.  What concerned me was that some  were interpreting this to mean that one need not try to work with parents because their children’s genetics run the show.  This flies in the face of the voluminous research stating that parenting is a primary factor major in children’s health and development and that working to improve parenting benefits children (for earlier posts on this see 1, 2, 34 & 5).  The study conducted by Reut Avinun and Ariel Knafo, from the Hebrew University of Jerusalem in Israel, was a meta-analyses of 32 published twin studies of parental behavior.  Twin studies can be used to ascertain the degree to which something is heritable, because identical twins share 100% of the same genes, where fraternal twins share only half the same genes.  The meta-analyses employed studies that assessed parenting using parent self report, child self report and observational measures.  The authors state in their abstract, “ meta-analysis of 32 children-as-twins studies of parenting revealed a heritability estimate of 23%, thus indicating that genetically influenced behaviors of the child affect and shape parental behavior.”

But It Depends on How Parenting is Assessed

This is what the press touted.  Though this conclusion was found only for the studies using self-report measures.  In the article’s discussion the authors more accurately state their findings:

While the child’s genotype was found to have an important effect on parenting whenever the latter was measured by either parent or child reports, it did not show a consistent effect on observed parental behavior. When parental positivity and negativity were assessed by observers, the effect of children’s genotype on parents was not significant.  Avinun and Knafo, 2013 page 11.

Similar to their findings with parental positivity or negativity, the authors found that a third dimension of parenting quality, maternal affect was reported to be significantly impacted by child genetics when self-reports were used, but not when directly assessed by observation.  Only for one of the four dimensions studied, maternal control, did studies using self-report or observation tools concur in finding a significant influence of child genetics.  

As I have discussed in a previous blog, parental self report shows low correlation with actual behavior.  Though Avinun and Knafo acknowledge that parent report is influenced by the image the parent has of himself or herself and other factors, they weight their interpretation of the research according to the results of the self-report studies.  It seems to me the weight should be placed on the actual observations conducted with validated parenting assessment tools, because independent trained observers directly assessed the behavior in real time.  It is very interesting that parents and children recollect differently, which opens important avenues for research and intervention.  

Parenting Interventions Matter

I read this particular article because I was concerned about the misinterpretation that, if parenting is significantly driven by the child’s genes, there would be no need to provide supports for parents to learn more nurturing behavior.  This erroneous interpretation might lead to cutbacks in parenting services. Rather, the important lesson from this meta-analysis is that the genetic influence is modest, at the very most.  If one accepts the 23%, it still means that 77% of parenting can be attributed to other factors that we can potentially influence.  That should buoy those of us who work so hard to help parents learn effective strategies for nurturing their children’s development. 

It is not surprising that genetically influenced factors, like temperamentplay an important role in shaping parent-child interactions.  After all, we know that each child is different in a number of ways.  The key for parents is understanding his or her child’s abilities and needs, then adapting their parenting strategies to each individual child.  During parent-child interaction in the early years, it is the adult who has a greater capacity than the child to learn, reflect and change.  Even if the child’s genetics influence some parenting behavior, we can support each parent to start where they are and move toward better nurturing of each and every child.  Take heart, this study shows that parenting is largely NOT determined by child genetics, so there’s plenty of opportunity for intervention to help parents meet each child’s needs.