Putting cash in the hands of mothers can help shape the brains of their babies, according to a study in the United States.
Family income has been linked to child development numerous times in the past in observational studies, but this is the first time researchers have found direct experimental evidence of how poverty drives such changes.
The findings come from an ongoing study known as Baby's First Year, which is attempting to assess how poverty reduction can impact the cognitive and emotional growth of very young children.
"We have known for many years that growing up in poverty puts children at risk for lower school achievement, reduced earnings, and poorer health," explains neuroscientist Kimberly Noble from Columbia University.
"However, until now, we haven't been able to say whether poverty itself causes differences in child development, or whether growing up in poverty is simply associated with other factors that cause those differences."
A thousand low-income mothers in the US were recruited for the study shortly after their babies were born.
These parents, who came from either New York City, New Orleans, Omaha or Minneapolis/St. Paul, were then randomly allocated either $333 a month in unconditional cash payments or $20 a month in unconditional cash payments for the first four years of their baby's life – no strings attached.
The data show that giving low-income mothers financial support can directly change infant brain activity in the first year of life.
Infants whose mothers had received the higher cash payments, for instance, had higher frequency brain activity than those infants whose mothers had received less.
Further research is needed to see whether these changes in brain activity last or whether they translate to improved cognitive development, but there's good reason to suspect they might.
Some small studies have recently shown that high-frequency brain activity is more common in babies born into higher-income families. This type of activity is also associated with higher language, cognitive, and social-emotional scores.
Because of the nature of the study, the authors still don't know what environmental factors could have triggered the higher frequency brain waves seen in the trial. They are now investigating whether household expenditures, parental behaviors, family relationships, or family stress had anything to do with the results.
The study was published in the PNAS.