What’s New in Psychology?
Poverty and Crime May Change the Brains of Babies
Jim Windell
Criminologists understand that there is a link between poverty and crime. However, it is generally thought that living in poverty and living in socially and economically disadvantaged neighborhoods is simply an environmental factor that has an impact on health and education while also restricting choices for rising out of poverty.
But what if living in a disadvantaged neighborhood actually changed the biology of people? Could this lead to public policies that might protect people from poverty and other disadvantages?
These are important questions that should be part of the conversation based on two new studies. These studies suggest that a mother’s exposure to poverty and crime may actually change the structure and function of the brains of newborns.
The first study was recently published online April 12 in the journal JAMA Network Open. Researchers used MRI scans on healthy newborns while they slept. The results of these brain scans indicated that babies of mothers facing social disadvantages, such as poverty, tended to be born with smaller brains than babies whose mothers had higher household incomes.
More specifically, MRI scans of full-term newborns born to mothers living in poverty revealed smaller volumes across the entire brain – including the cortical gray matter, subcortical gray matter and white matter – than found in the brains of babies whose mothers had higher household incomes. These brain scans, which were conducted only a few days to weeks after birth, also showed evidence of less folding of the brain among infants born to mothers living in poverty. Other research has found that fewer and shallower folds typically signify brain immaturity. The healthy human brain folds as it grows and develops, providing the cerebral cortex with a larger functional surface area.
A second study of data from the same sample of 399 mothers and their babies – this one published online recently in the journal Biological Psychiatry – reports that pregnant mothers from neighborhoods with high crime rates gave birth to infants whose brains functioned differently during their first weeks of life than babies born to mothers living in safer neighborhoods. Functional MRI scans of babies whose mothers were exposed to crime displayed weaker connections between brain structures that process emotions and structures that help regulate and control those emotions. It is possible that maternal stress could be one of the reasons for the weaker connections in the babies' brains.
According to Christopher D. Smyser, M.D., a professor of neurology, of pediatrics and of radiology at Washington University School of Medicine and a lead investigator in both studies, “These studies demonstrate that a mother's experiences during pregnancy can have a major impact on her infant's brain development. Like that old song about how the 'knee bone is connected to the shin bone,' there's a saying about the brain that 'areas that fire together wire together.' We're analyzing how brain regions develop and form early functional networks because how those structures develop and work together may have a major impact on long-term development and behavior.”
First author Regina L. Triplett, M.D., a postdoctoral fellow in neurology, reported that she had expected to find that maternal poverty – referred to in the paper as social disadvantage – could affect the babies' developing brains. She also expected to see effects from psychosocial stress, which includes measures of adverse life experiences as well as measures of stress and depression. “Social disadvantage affected the brain across many of its structures, but there were not significant effects that were related to psychosocial stress,” Triplett said. “Our concern is that as babies begin life with these smaller brain structures, their brains may not develop in as healthy a way as the brains of babies whose mothers lived in higher income households.”
In the second study, which implicated living in high-crime neighborhoods as a factor in weaker functional connections in the brains of newborns, first author Rebecca G. Brady, a graduate student in the university's Medical Scientist Training Program, found that unlike the effects of poverty, the effects of exposure to crime were focused on particular areas of the babies' brains. “Instead of a brain-wide effect, living in a high-crime area during pregnancy seems to have more specific effects on the emotion-processing regions of babies' brains,” Brady said. “We found that this weakening of the functional connections between emotion-processing structures in the babies' brains was very robust when we controlled for other types of adversity, such as poverty. It appears that stresses linked to crime had more specific effects on brain function.”
It is already true that reducing poverty and lowering crime rates are well-established goals of public policy and public health. However, the researchers for these studies, while agreeing that reducing poverty and lowering crimes are very important for various reasons, also think that in order to help people reach their full potential policies must focus on assisting people even before they are born.
As Smyser sees it, “Several research projects around the country are providing money for living expenses to pregnant mothers now, and some cities have determined that raising pregnant mothers out of poverty is good public policy. The evidence we're gathering from these studies certainly would support that idea.”
To read these articles, find them with these references:
1. Regina L. Triplett, Rachel E. Lean, Amisha Parikh, J. Philip Miller, Dimitrios Alexopoulos, Sydney Kaplan, Dominique Meyer, Christopher Adamson, Tara A. Smyser, Cynthia E. Rogers, Deanna M. Barch, Barbara Warner, Joan L. Luby, Christopher D. Smyser. (2022). Association of Prenatal Exposure to Early-Life Adversity With Neonatal Brain Volumes at Birth. JAMA Network Open, 5 (4): e227045 DOI: 10.1001/jamanetworkopen.2022.7045
2. Rebecca G. Brady, Cynthia E. Rogers, Trinidi Prochaska, Sydney Kaplan, Rachel E. Lean, Tara A. Smyser, Joshua S. Shimony, George M. Slavich, Barbara B. Warner, Deanna M. Barch, Joan L. Luby, Christopher D. Smyser. (2022). The Effects of Prenatal Exposure to Neighborhood Crime on Neonatal Functional Connectivity. Biological Psychiatry, DOI: 10.1016/j.biopsych.2022.01.020
