New research finds that domestic violence in first six years has direct impact on IQ

by Freya Lucas

November 27, 2019

New research shared by the University of Manchester has found that children of women who reported domestic violence in pregnancy, or during the first six years of the child’s life, are almost 50 per cent more likely to have a low IQ at eight years of age.


The research will be of interest to those working to support children and families in the first six years of life, including through their work in early childhood education and care. 


University of Manchester epidemiologists found that in a control group of children, that is those whose mothers did not experience domestic violence, 13 per cent of children had an IQ of below 90 at eight years of age.


This figure rose to 22 per cent in children whose mothers had experienced physical violence from their partner either in pregnancy or during the first six years of the child’s life. The chance of a low IQ rose to nearly 35 per cent in the event that the mother was repeatedly exposed to domestic violence.

That means children with mothers who repeatedly suffer domestic violence during pregnancy and the first six years of their child’s life are almost three times more likely to have a low IQ at 8 years of age, researchers said.

Low IQ is defined as a score of 90 or less, with normal IQ considered as 100 or more. The intelligence of the children studied in the research was measured at eight years using the Weschler standardised IQ test.


The study examined the link between domestic violence – also called intimate partner violence (IPV) – and child intelligence at 8 years old, using 3,997 mother child pairs from The University of Bristol’s Avon Longitudinal Study of Parents and Children (ALSPAC).


Speaking about the findings, lead researcher Dr Kathryn Abel said that while there was a body of research demonstrating that intelligence in childhood is strongly linked with doing well in adulthood, there has been little evidence about the risk of low IQ for these children.


“While we cannot conclude that IPV causes low IQ, these findings demonstrate domestic violence has a measurable link, by mid-childhood, independent of other risk factors for low IQ,” she added. 


The study, funded by the Wellcome Trust and Medical Research Council, is published in Wellcome Open Research.