How a lack of parental care can disrupt brain development in children

Children left behind by parents for extended periods show larger gray matter volume than children whose parents don’t leave for long stretches of time. And that has ramifications for IQ, emotional development and maturity, according to the research presented last week at the annual meeting of the Radiological Society of North America.

The role that care plays in a child’s brain development has been the subject of ongoing international research.

“Throughout the world, due to political upheaval, economic necessity or other reasons, parents sometimes are compelled to travel away from home for months or years at a time, leaving their children behind,” according to a Science Daily release on the new study.

In China, where such absences happen frequently as parents search for better jobs, researchers examined how the extended leaves affect children left with grandparents or other adults for more than six months at a time.

“We wanted to study the brain structure in these left-behind children,” said study author Yuan Xiao, a doctoral candidate at Huaxi MR Research Center and a radiology researcher at West China Hospital of Sichuan University. “Previous studies support the hypothesis that parental care can directly affect brain development in offspring. However, most prior work is with rather severe social deprivation, such as orphans. We looked at children who were left behind with relatives when the parents left to seek employment far from home.”

Looking at children ages 7 to 13, they found that gray matter volumes were larger in specific parts of the brain, including emotional brain circuitry, compared to kids who had been consistently living with their parents. They found that larger gray matter volume in the part of the brain where memory encoding and retrieval takes place was “negatively correlated” with IQ score.

The researchers concluded that the larger volume could indicate “insufficient pruning and maturity of the brain,” which could mean that growing up without parental involvement may slow down brain development.

“Our study provides the first empirical evidence showing that the lack of direct parental care alters the trajectory of brain development in left-behind children,” Xiao told the PsyBlog. “Public health efforts are needed to provide additional intellectual and emotional support to children left behind by parents.”

It has been nearly a decade since a study led by researchers at Tulane University looked at caregiving’s impact on the brains of young children. The research team, which included scientists from Harvard, University of Maryland and Temple University, looked at children ages six months to 30 months who were abandoned to Romanian orphanages shortly after birth. They found that children placed in foster care before 18 months of age had higher IQs at 42 months than those placed later.

“Our findings suggest that there may be a sensitive period in the first two years of life in which experiences are especially important in shaping cognitive development,” principal investigator Charles Zeanah, professor of child development at Tulane, said in a news release at the time. “This work adds to a growing body of scientific evidence about the importance of early relationship experiences.”

They concluded foster care is better than institutional care, no matter what country.

A report by Zero To Three and the Ounce of Prevention fund offers suggestions for boosting early brain development. “Starting Smart” examines how a child’s earliest experiences impacts ongoing brain development and offers suggestions for helping children.

“Children who receive sensitive, responsive care from their parents and other caregivers in the first years of life enjoy an important head start toward success in their lives,” the report stated. “The secure relationships they develop with the important adults in their lives lay the foundation for emotional development and help protect them from the many stresses they may face as they grow.”