The nature versus nurture debate is not a new one; how much of who were are is determined by our genes, and how much of it comes from our environment? While the debate is far from settled, new research reported in Behavior Genetics has added weight to the idea that our genes influence some of our morals and beliefs. While parents are clearly important to the development of responsible and conscientious adults, the work suggests that there is a genetic factor in these characteristics.
One of the researchers involved in this work, Amanda Ramos, a Training Interdisciplinary Educational Scientists fellow at Penn State, is hopeful that this work will help start a discussion about why and how a so-called “virtuous character” develops, and how genes influence it.
“A lot of studies have shown a link between parenting and these virtuous traits, but they haven't looked at the genetic component,” noted Ramos. “I thought that was a missed opportunity because parents also share their genes with their children, and what we think is parents influencing and teaching their children these characteristics may actually be due, at least in part, to genetics.”
Research has established that virtuous qualities such as conscientiousness and social responsibility are linked to civic engagement and well-being. These traits have been promoted with school-based interventions, which don’t work for everyone. Ramos was interested in why these traits develop in some people but not others and whether genetics plays a role.
When researchers want to know whether genetics play a role in some trait, they can use a twin study. If both identical twins always carry some trait, the trait is very likely due to genes. In this work, other siblings with different degrees of relatedness were included. That can help shed light on the influence of genes as well as the environment. Step-siblings, e.g., share a home environment but don’t have the same genes.
“If identical twins are more similar than fraternal twins, for example, it's assumed there's a genetic influence," explained Ramos. "Including multiple degrees of relatedness can give you more power to disentangle the genetic influences from the shared environment.”
In this work, data was first gathered during the participants’ adolescence and next during young adulthood. The scientists measured the levels of conflict (or parental negativity), and praise (or parental positivity), and virtuosity, (or adolescent responsibility and conscientiousness) in young adulthood. Although positive parenting was found to be connected to more responsible and conscientious children, that association was stronger in more closely related siblings. The siblings have a genetic similarity, suggesting to Ramos that these traits are due in part to genetics.
“Essentially, we found that both genetics and parenting have an effect on these characteristics," Ramos said. "The way children act or behave is due, in part, to genetic similarity and parents respond to those child behaviors. Then, those behaviors are having an influence on the children's social responsibility and conscientiousness.”
“Most people assume that parenting shapes the development of virtuous character in children via entirely environmental pathways," said Jenae Neiderhiser, Distinguished Professor of Psychology and Human Development and Family Studies at Penn State. “But our results suggest there are also heritable influences. This doesn't mean that if parents are conscientious that their children also will be regardless of how the children are parented. It does mean, however, that children inherit a tendency to behave in a particular way and that this shouldn't be ignored.”
These traits, noted the researchers, are not only due to our DNA. “Your genes are not totally deterministic of who you are," Ramos said. "Genes simply give you a potential. People still make their own choices and have agency in shaping who they become.”
Learn more about behavioral genetics from the podcast video.