Research: Parenting Buffers Brain’s Hippocampus from Poverty’s Impact

POSTED BY: PHIL GORDON ON THU, OCT 31, 2013

This week I want to highlight an exciting new study just published in the Journal of the American Medical Association Pediatrics by Joan Luby and coworkers entitled The Effects of Poverty on Childhood Brain Development: The Mediating Effect of Caregiving and Stressful Life Events.  The study was a prospective longitudinal study of 145 children, starting in preschool and following them into middle school. The children’s brains were scanned by magnetic resonance imaging to assess brain architecture when the children were 5 to 10 years old.  As other neuroimaging studies have shown, poverty predicted reduced volumes of cortical gray and white matter, amygdala and hippocampus.  What is new and intriguing about this study is that it examined the influence of three psychosocial factors, parental education, stressful life events, and caregiving (i.e. parenting).  Remarkably, the study showed that caregiving support/hostility mediated the reduction in both right and left hippocampus volume.  Stressful events mediated only left hippocampus volume.  Though parent education is highly touted as a mediator of children’s development, parent education alone was not shown to significantly mediate the reduced volume in any region of the brain.  Put simply, this study shows that parenting is so important to development of one part of the brain, the hippocampus, that differences can be seen structurally, using magnetic imaging.   

Why the Hippocampus Matters   

The hippocampus is critical to the processing of short-term memory.  You have to have short-term memory to build long-term memories, so the hippocampus is critical to learning.  Someone with a damaged hippocampus can retrieve long-term memories, but can’t make new ones.  Also, there is considerable evidence that the hippocampus is both important in adapting to stress, and is negatively impacted by stress.  

Luby et al.’s finding involving parenting and the hippocampus, reminds me of the work of Jack Shonkoff, at the Center for the Developing Child at Harvard, that we discussed in a previous blog.

Toxic stress response can occur when a child experiences strong, frequent, and/or prolonged adversity—such as physical or emotional abuse, chronic neglect, caregiver substance abuse or mental illness, exposure to violence, and/or the accumulated burdens of family economic hardship—without adequate adult support. Center for the Developing Child

Now we can say parenting protects not only from the impacts of toxic stress, but also buffers the hippocampus from the impacts of poverty, which certainly includes toxic stress as a component.

Luby and coworkers bravely extended the discussion of their research results to policy implications.

…attempts to enhance early caregiving should be a focused public health target for prevention and early intervention. Luby et al. 2013

This study may also provide a physical manifestation of what Isabel Sawhill and coworkers at the Brookings Institution referred to as a “Parenting Gap” causing the achievement gap.  Sawhill and colleagues also argue for policies focused on parents.

There is an important distinction to be made here: The state cannot and must not take over the job of raising children—but the state can and must do more to help parents raise their own. . . the consequences of failure in parenting are felt not just by individual children but by society at large, in the form of welfare payments, higher crime, and lost productivity. Sawhill, Reeves & Howard, 2013, page 7

Luby and coworkers also echoed statements made by the Noble Prize-winning economist James Heckman, 

The proper measure of disadvantage is not necessarily family poverty or parental education. The available evidence suggests that the quality of parenting is the important scarce resource. So we need better measures of risky family environments in order to achieve more accurate targeting.  -James Heckman, page 35

Assessing Parenting Is Key to Addressing Poverty

The research is overwhelming; parenting is important in shielding children from the negative effects of poverty.  The calls for policies supporting parents are growing continually stronger and more frequent.  Investing in supporting parenting quality is worth it, because it has benefits over a lifetime and across future generations.  Without parenting assessment measures, interventions are working in the dark.  Validated parenting assessment tools, can show you where a parent is starting, guide you in tailoring your services to meet each specific family’s needs, improve your parenting outcomes, and document success.