According to researchers in the UK, how much a child's head grows by the time he or she reaches age one may be an indication of a child's intelligence.
The researchers from the University of Southampton, in England say although they do not know exactly what causes some babies to have bigger brains than others, the brain volume a child achieves by the age of one year helps determine later intelligence.
Lead author Catherine Gale, PhD, of the University of Southampton says head growth, especially in infancy may be one of those factors.
Gale and her team studied 633 full-term British babies from the Avon Longitudinal Study of Parents and Children.
They measured with a tape measure the babies' head circumference at birth, one year, four years, and eight years.
The children were given Wechsler Preschool and Primary Scale of Intelligence at the age 4 years old and the Wechsler Intelligence test at 8 years of age and it was found that those with the biggest heads achieved the highest IQ scores.
The researchers suggest that brain growth after infancy, at least in terms of brain volume, is unlikely to compensate for poor growth in the first year of life and did not seem to be as significant.
For the study the researchers also studied the babies' parents; mothers were asked to complete surveys about their parenting style, their older children, and other factors such as breastfeeding and postpartum depression and each mother was given a parenting score based on the survey results.