Measuring the “long-arm” of childhood

An interview with Laurel Raffington about her research
 

A new study indicates that children who grow up in socially disadvantaged families tend to have epigenetic profiles associated with poorer outcomes in adults. In this interview, first author Laurel Raffington contextualizes the study results and speaks about future research projects. She also speculates about what her research implies for the current debate on basic child financial security (“Kindergrundsicherung”) in Germany.
 

Since August 2022, you direct the Max Planck Research Group Biosocial – Biology, Social Disparities, and Development. What is your research about?

Laurel Raffington: Social inequality is a global problem that comes in differing degrees of severity and has many different forms and expressions, including classism, sexism, and racism. Children who grow up in socially disadvantaged families that are marginalized through poverty or racism, for example, are at an increased risk of suboptimal childcare, educational resources, healthcare, and nutrition, as well as higher exposure to environmental toxicants, family stress, and neighborhood threats. Accordingly, children in socially disadvantaged families tend to be at increased risk for obesity, psychopathology, and lower educational performance. Gene-environment interplay can be seen as the primary mechanism by which social inequality affects child and adolescent development shaping differential outcomes of education, health, and well-being across the lifespan. We leverage recent innovations from human genomics to study gene-environment interplay developmentally, which may highlight environmental mechanisms we can intervene on.

Your work demonstrates that children who grow up in socially disadvantaged families tend to have epigenetic profiles associated with poorer outcomes. What does that mean?

Epigenetic mechanisms regulate gene-environment interplay. Our research shows that children raised in socioeconomically disadvantaged households and neighborhoods exhibited epigenetic profiles that, in previous studies of adults, were associated with worse health, like heightened obesity risk, advanced biological age, and lower cognitive abilities. We found this by examining data from over 3,000 individuals aged 8 to 18 from two large-scale U.S. studies. Our findings are in line with theories of epigenetic regulation of later life health and well-being. They also suggest that poverty very early in life, e.g., at birth, may be especially important to epigenetic profiles of later life health.

Do the study results allow conclusions to be drawn for social policy measures?

It may be valuable for future studies assessing the impact of social policies in childhood to incorporate epigenetic measures as outcomes that are potentially informative about future health payoffs. This is why we are collaborating with the Baby’s First Years Study, a randomized controlled trial in which mothers receive monthly cash gifts during their child’s first six years of life. We are investigating whether receiving these cash gifts in early childhood affects children's epigenetic profiles of health and well-being. The study already found that mothers who received cash gifts increased their spending on and time spent with their young children. There was no evidence that mothers spent more money on alcohol or tobacco, as is often purported by what I think of as the “blaming-the-mother” model of social inequality.

Can the results also be applied to Germany?

Generally, we think of gene-environment interplay as context-specific. The social and political landscape matter greatly to how genetic influences are expressed in terms of life course outcomes. Thus, we cannot assume that findings transfer across countries without empirically probing this. Some of the most interesting behavior genetic research tracks how genetic effects differ between countries depending on their social systems.

Poverty is a relative social measure. Globally, Germany is a rich country. But non-negligible income inequality, childhood poverty, and intergenerational educational gaps have persisted within Germany for decades. Accordingly, we have found associations of socioeconomic inequality with epigenetic profiles of biological aging, health, and mortality in a German sample that widely ranged in age (Clinical Epigenetics, 2023). In another German study of ours, we observed that financially poorer parents were more at risk of high stress levels, and this seemed to tinker down to their children ( (Developmental Cognitive Neuroscience, 2019; Psychoneuroendocrinology, 2018).

Animal research indicates that pathways from social inequality to well-being via accelerated biological aging are shared across a range of social mammals. Thus, gene-environment interplay is context-specific, but some biological mechanisms may be widely shared across human and non-human societies.

In Germany, there is currently a lot of discussion about basic child security (“Kindergrundsicherung”) to combat child poverty. What do you think of this in light of your work?

Many social epidemiologists and developmental psychologists, myself included, think of poverty as a fundamental cause of disparities in population health and education. Improving the financial resources available to families living in or near poverty, for instance, through a well-financed, widely accessible “Kindergrundsicherung,” is clearly in line with decades of research aimed at improving population health and education across generations.

Given our recent research and work by colleagues, I would be keen to see whether providing financial support beginning before birth, for example, by initiating a “Kindergrundsicherung” payment to pregnant women experiencing financial hardships, would improve epigenetic profiles associated with health and well-being in their babies. Given the rapid pace of very early life development, alleviating mothers' financial strain in pregnancy may have pronounced long-term benefits for both babies and their mothers.

Among other things, you work with the analysis of saliva samples. What are the advantages of this method?

Blood is considered the gold-standard tissue to quantify epigenetic processes. But, hard-to-reach samples, including samples of children, often do not want to donate blood, which can result in unrepresentative and small samples. Saliva samples are substantially less invasive and easier to collect. Because epigenetic patterns differ by tissue type, it was unclear whether epigenetic measures would be a valid measure when computed in saliva rather than blood DNA. But our results reported here clearly show that saliva epigenetic measures are valid biomarkers of at least some health and psychological outcomes.

What are you working on next? What is your future research program?

Over the next year, we will evaluate whether these epigenetic measures are sensitive to cash gifts received as part of the Baby’s First Years Study. We will also probe to what degree they change over childhood, in association with physical and psychological differences, and how they compare with other DNA-based measures. We’ll see where the science takes us.

In terms of science communication, we are noticing that genetics and genomics is gaining attention in the public. We are keen on helping people think about gene-environment interplay as it relates to complex human outcomes and implications for how our societies are currently – and could be – structured.

You are also involved in the team of Equal Opportunity Officers at the institute. What motivated you to do this?

Science is a public good. In order to generate impactful science for the greater good, the scientific workforce needs to reflect the experiences and perspectives of different members of society, because those scientists are more likely to do science that serves those groups. For example, why do we know so little about menopause even though it affects 50 percent of the global population? Why is there barely any research on racism in Germany?

German science leadership is not yet representative of our society. I hope that our equal opportunities team can help support ongoing efforts to make German science and academia more inclusive to individuals from commonly underrepresented groups.#

About
In 2022 Laurel Raffington started an independent Max Planck Research Group named Biosocial – Biology, Social Disparities, and Development at the Max Planck Institute for Human Development. She is a German-American developmental psychologist. Her research examines how social inequality affects child and adolescent development at multiple biological and psychological levels. Laurel Raffington received her Ph.D. in psychology from the Humboldt-Universität zu Berlin whilst working at the Max Planck Institute for Human Development. Her dissertation was awarded the Otto-Hahn-Medal by the Max Planck Society and the Margret-and-Paul-Baltes Prize by the German Psychological Society. She then joined the labs of Prof. Kathryn Paige Harden and Prof. Elliot Tucker-Drob as a postdoctoral researcher at the University of Texas at Austin, Population Research Center. 

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