The results of the study appeared in the European Journal of Public Health.
Researchers say the data indicates babies who are bottle-fed or breast-fed on a schedule tend to underperform their peers who were fed simply when they were hungry. The difference in IQ levels was as high as five points, which researchers called very significant.
Dr. Maria Iacovou, who led the study, was quoted on the above website. "At this stage, we must be very cautious about claiming a causal link between feeding patterns and IQ. We cannot definitively say why these differences occur, although we do have a range of hypotheses. This is the first study to explore this area and more research is needed to understand the processes involved," she said about any possible connection.
One hypothesis with the researchers: schedule-feeding is more common among mothers who are younger, single, less educated, or who do not have the time to read to their children.
Again, the researchers say, it is just a hypothesis, with more studies needed.