Big babies are brainier

By Merill Haseen

IT SEEMS that brains are something you're born with, after all. New research shows that the bigger the baby when it's born, the brainier it is likely to be.

�

Four thousand people who were born in 1946 were given cognitive tests at ages eight, 11, 15, 26 and 43. These included measurements of reading ability, arithmetic skills, non-verbal reasoning, memory, thinking-speed and concentration. The results show that bigger babies tend to grow up brighter, do better at school and are cleverer in adulthood than their smaller peers.

�

Even at age 26, those who were bigger babies performed better than those who were smaller at birth, after correcting for other factors such as social class, mother's education and birth order.

�

By age 43, however, the effects of birth weight had mostly disappeared. The researchers put this down to adult environmental influences, particularly educational and career achievements, which overshadow any birth factors by this age.

�

One theory for this difference between large and small babies is to do with the size of the brain - bigger babies have bigger heads, and bigger brains are brighter. As the head is the heaviest part of a baby - head circumference is strongly related to birth weight - brainy babies weigh more.

�

Marcus Richards of University College London, who led the study, warned that parents of small babies should not worry about their children's future success: 'There are many postnatal factors which affect the outcome,' he says, 'and the extent to which parents are involved in their children's education is a major one.'

• Low birthweight babies
  The three biggest risk factors which could lead to low birthweight in babies are poor nutrition, smoking and alcohol misuse.
  
• Statistics also show that babies of teenager mothers are more likely to have a low birthweight, as are babies born to poorer families.
  �