Non-inherited genes affect children’s development

(Press-News.org) Parents’ genes – even when not directly inherited by a child – may play a role in their educational and mental health outcomes, finds a new report by UCL researchers.

The report, Understanding the intergenerational transmission of educational (under)achievement, which was funded by the Nuffield Foundation, evaluated how parental genetics can influence child development through the environment provided by their parents (for example, reading habits or access to better resources), also known as “genetic nurture” or “indirect genetic effects”.

The researchers reviewed 12 published studies, involving 38,654 families from the UK, Australia, the Netherlands, Iceland and the United States, alongside performing an original analysis using genetic data from 4,580 families in the UK.

They then used a statistical tool called polygenic scoring to summarise the cumulative effect of hundreds of thousands of genetic variants across the genome (a person’s complete set of genetic instructions) that are associated with particular traits, such as educational attainment.

They found that parental polygenic scores for education had a strong effect on children’s educational outcomes, such as years of education completed or school grades, even after accounting for genetic transmission.

This is because parents with a higher genetic predisposition toward education may be more likely to read to their children or invest in learning resources. These behaviours can positively affect the child, regardless of whether they inherited the relevant genes.

The researchers also found a tentative link between non-inherited genes and mental health traits, including hyperactivity and inattention, emotional symptoms, conduct problems, and peer problems, or prosocial behaviour (e.g. helping others, sharing, showing empathy, and comforting someone in distress).

The strongest effects were found around the age of three and involved parental genetic predispositions for traits such as motivation, perseverance, emotional regulation, and self-control (e.g. non-cognitive skills).

This finding suggests that parents with better non-cognitive skills may be especially able to support their children early in life.

For both educational and mental health related outcomes, indirect genetic influences were stronger in early childhood.

Co-investigator Dr José J. Morosoli (UCL Psychology & Language Sciences) said: “Through this project, we show how genetics and environment are deeply intertwined, challenging the idea that inherited genetics alone determine outcomes.

“We found that both direct inheritance of genes and the environment shaped by parents’ genetics influence children’s education and mental health. Ignoring these indirect genetic effects can lead to misleading conclusions.

“Additionally, the impact of genetics and environment changes as children grow, suggesting that early interventions focusing on parents might prove fruitful, while later efforts could benefit from targeting the children themselves.”

When the team accounted for family socioeconomic status and parental education, indirect genetic effects dropped by approximately 75%.

This suggests that the effect of non-inherited genes was largely explained by family socioeconomic position and parental education.

For example, parents with higher socioeconomic status and education levels may have access to the necessary resources to provide their children with opportunities linked to better outcomes - regardless of genetic factors.

As a result, the researchers are calling for future studies to explore the specific resource-based disparities that drive educational underachievement.

Principal investigator Professor Jean-Baptiste Pingault (UCL Psychology & Language Sciences) said: “Our findings echo evidence that family resources and opportunities partly shape children’s developmental outcomes – further illustrating the importance of providing consistent and developmentally appropriate support to children and their families.

“This research supports the UK Government’s calls for life-course approaches to mental health and development, highlighting the importance of early intervention and sustained support throughout childhood.”

Study limitations

It is critical to stress that the genetic effects found in the report are small and not deterministic. They cannot be used to make individual predictions or guide education policy. The value of this work lies in improving our understanding of human development and informing better research into the causes of traits and behaviours, especially research aiming to understand the interplay between social and biological factors

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