This is a first study, not yet confirmed.

Feeding Your Baby On Demand 'May Contribute to Higher IQ'

A new study suggests that babies who are breast-fed or bottle-fed to a schedule do not perform academically as well at school as their demand-fed peers.

"The difference between schedule and demand-fed children is found both in breastfed and in bottle-fed babies," explains Dr Iacovou.

"The difference in IQ levels of around four to five points, though statistically highly significant, would not make a child at the bottom of the class move to the top, but it would be noticeable. To give a sense of the kind of difference that four or five higher IQ points might make, in a class of 30 children, for example, a child who is right in the middle of the class, ranked at 15th, might be, with an improvement of four or five IQ points, ranked higher, at about 11th or 12th in the class."