Can parent arguments hurt a child’s mental development?

As the African proverb says: When elephants fight, it’s the grass that suffers.

Well, that reminder about innocent bystanders is also true for marriage: When married couples fight, it’s the children who suffer, new research says.

When children in two-parent homes are exposed to their parents’ frequent, intense conflicts, it affects a part of their stress response called respiratory sinus arrhythmia (RSA). This is a measure of how the heart rate synchs with breathing. It is part of the stress response that has been linked to our ability to regulate emotions and attention, which is key for cognitive development.

Researchers from Auburn University and the Catholic University of America talked to 251 children, all 8 years old, about their parents’ fighting. Then, the researchers looked at how their stress response, measured by the RSA, affected their cognitive development until age 10, specifically rapid problem solving and pattern recognition.

For the eight-year-olds with a low resting RSA, more exposure to marital conflict seemed to lead to a less adaptive RSA at age 9. Children with a lower RSA at the start of the study who had less adaptive stress responses showed slower intellectual and mental development.

The study was published in the March 27 issue of the journal Child Development.

Authors say the results could mean that fighting parents cause more than just emotional issues. “The findings provide further evidence that stress affects the development of the body’s stress response systems that help regulate attention, and that how these systems work is tied to the development of cognitive ability,” said researcher J. Benjamin Hinnant, assistant professor of psychology at the Catholic University of America, in a statement.