American researchers from Children’s Hospital Boston, Harvard Medical School, in Boston and the University of Minnesota, tracked the development of 206 children from birth to the age of eight, who were taking part in the Minnesota Longitudinal Study of Parents and Children - an ongoing study into which factors influence individual development.
They interviewed and observed mothers interacting with their children at home and in a laboratory every few months, along with reviewing medical and child protection records.
Children’s intellectual development was also assessed at the age of two, five and eight-years-old.
Their findings revealed that nearly one in three children had been maltreated and/or witnessed violence against his/her mother by the age of five.
Children who had suffered emotional trauma scored lower on cognitive tests, especially those who had been maltreated or witnessed violence during their first two years of life, scoring on average 7.25 points lower.
The authors of the study say that their findings echo those of other researchers who have indentified changes in brain activity and structure associated with trauma and adversity in early life.
The study, Interpersonal trauma exposure and cognitive development in children to age 8 years: a longitudinal study, is published online in the Journal of Epidemiology and Community Health.