Head Size and Intelligence
In August we discussed some of the new data showing an association between the hormone insulin-like growth factor 1 (IGF-1) and a child’s IQ.
Now new research from the University of Southampton in England has found an association between skull size and intelligence. It seems that the brain volume a child achieves by the age of 1 year helps to determine his or her later intelligence.
The study of 633 newborns born at term has found that those with larger heads scored better on intelligence tests at the age of 4. And those children whose heads were larger than the average at age 8 also had higher IQs. Children who put on a spurt of skull growth after the age of 8 did not show a catch up in their IQ scores, implying that there is a critical period for skull growth, brain and cognitive development.
The researchers also studied the babies’ parents. The babies’ mothers completed surveys about their parenting style, their older children, and other factors such as breastfeeding and postpartum depression.
The babies tended to have higher IQ scores if they had been breastfed for three or more months, if their parents had more education and if they had mothers with high scores on the questionnaire that looked at parenting style.
Even after adjusting for all those factors, babies’ head growth by age 1 remained tied to IQ scores among the 4- and 8-year-olds.
It is also known that older people with a larger head circumference tend to perform better in tests of cognitive function and may have reduced risks of developing Alzheimer’s disease. The protective seeds are sown in the first eight years of life. But there is still much that can be done later in life to protect against the development of Alzheimer’s disease.
Two years ago the same researchers showed that there are critical periods in brain growth and cognitive function in children. Brain growth during infancy and early childhood is more important than growth during fetal life in determining cognitive function. And as we have discussed before in my writings about epigenetics, the food that a child eats, the chemicals that he or she ingests and the attitude of his or her parents and peers can all change the way in which their genes function. Positive influences during the first few formative years can have a massive impact on cognitive function throughout life. But even if a child is exposed to an adverse environment, there are still good chances for repairing the damage throughout life.
Biology is not destiny!
“Intellect annuls fate. So far as a man thinks, he is free.”
–Ralph Waldo Emerson (American Poet and Essayist, 1803-1882_