Peer-reviewed article
The nature of nurture: Effects of parental genotypes
Augustine Kong, Guðmar Þorleifsson, Michael L. Frigge, Vilhjalmsson Bj, Young Ai et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This peer-reviewed study examines how parental genetic make-up influences child outcomes indirectly through parenting and nurturing, beyond direct genetic inheritance. The research demonstrates that parental genes affect long-lasting traits in children including educational attainment, height, BMI, and smoking behaviour. The study also quantifies how assortative mating (choosing genetically similar partners) inflates estimates of direct genetic effects. The findings emphasize that genes do not solely determine outcomes and that lifestyle choices can modify genetic susceptibilities.
Key points
- Parental genetic effects on child outcomes operate indirectly through how parents care for and nurture children, not just through direct genetic inheritance
- Parental genotypes influence multiple long-lasting traits: educational attainment, adult height, BMI, age at first child, and cigarette smoking
- Maternal genetic effects on nurturing are stronger than paternal effects, particularly for nutritional and health-related traits
- Assortative mating (partner selection based on genetic similarity) is another source of overestimating direct genetic effects
- Lifestyle and health choices can modify genetic susceptibilities in both individuals and their children
Limitations
This is a genetic epidemiology study focused on mechanisms of inheritance rather than child well-being outcomes or interventions. It does not evaluate any specific programmes or policies designed to improve child health or development, and cannot inform us about effectiveness of child-focused interventions.
Abstract
This ground-breaking study shows that your genetic make-up may influence your appearance, behaviour and health risks, not only by acting directly on your biology, but also indirectly, through the effects on your parents and how they cared and “nurtured” you. Such parental effects are obvious for very early life traits, such as birth weight, where there are well-known examples of maternal alleles that alter pregnancy glycaemia and hence influence fetal growth and adiposity. However, here, similar effects are shown for many long-lasting traits, including educational attainment, adult height and BMI, age at first child, and cigarette smoking. Unsurprisingly, for many nutritional and health-related traits, they found that mothers have stronger nurturing effects than fathers. Although not studied here, similar indirect effects could manifest between siblings. These indirect effects inflate estimates of the direct effects of genetic variants. Furthermore, the analyses allow quantification of the effects of another source of such overestimation, that due to assertive mating – which is the phenomenon whereby we choose partners who are more likely to resemble ourselves both physically and mentally. The findings highlight the importance of family data and underline the important message that our genes do not totally determine our behaviours and health outcomes. We have the power to modify our genetic susceptibilities through our lifestyle and health choices, both for ourselves and for our children.