On a webinar, hosted on Thursday, February 10, 2022, new research, the First Randomized Controlled Trial of Poverty Reduction in Early Childhood, focused on the impact that cash assistance to families can have on infant brain development. Presenters Sonya Troller-Renfree and Greg Duncan outlined findings that expands the understanding and the implications of poverty on child brain development and whether causal impacts can be drawn in regard to interventions.


The researchers recruited 1000 low-income mothers from 12 hospital maternity wards across several cities in the US. Upon enrollment in the study, mothers began receiving unconditional cash gifts for 52+ months via a debit card. The mothers were randomized into two groups; one was a high cash gift group who received $333/month, and one was a low cash gift group who received $20/month. Data was collected on the infants over a span of 4 years. During this study, the scientists used unprecedented and successful mobile EEG data collection to gather data from 435 infants.


Two developmental theories were examined as to how the monetary interventions would support families and infants. The first theory was that cash support would offer economic investments that parents could spend on their children which would translate to material goods spent on promoting child development. The other theory was that cash support would provide reduced stress for families which would alleviate some poverty and result in benefits for child development.


Brain development is most rapid in the first years of our lives, with brain cells increasing exponentially in number and the connections built between cells. Evidence from human and animal studies show that experiences shape how these processes take shape which can be seen in Electroencephalogram (EEG) tests. EEG tests show lower frequency power bands earlier in development which grow to higher frequency power bands later on.


In examining the impact of poverty, if you look at infants right after birth there are no socioeconomic disparities in brain function. These disparities begin to show within the first few years of life with children of lower income families having more lower frequency power bands and less higher frequency power bands.


Researchers found statistically significant results in the higher frequency bands which reflect more brain activity. More activity was seen in those infants whose mothers received higher cash gifts as compared to mothers who received lower cash gifts. The area of the brain where the activity was centralized was located in the frontal lobe and central brain regions which are those regions corresponding to learning, cognition, language and attention; it seems reasonable that these are areas that might be more impacted by poverty than areas such as vision. Qualitatively, it appeared as though in regards to the initial two theories, more impact was had through economic investments than stress reduction in terms of improving child development.


The presenters suggested that further research will have to be done a bigger sample size to make definitive and broader conclusions as to causal effects on cognition and subsequent policy implications such as whether the cash payments made in the study can be compared to government payments such as the Child Tax Credit. The nature of this study was sound, given that it was a randomized control study that took on a longitudinal design with both brain and behavioral outcomes and cutting-edge methods. Further research might take an interest in how the effects of cash payments play a role in specific subgroups of mothers perhaps by race or ethnicity.