a. Higher IQ Children who had consumed mother's milk by tube in early weeks of life had a significantly higher IQ at 7.5 to 8 yr.. than those who received no maternal milk, even after adjustment for differences between groups and mothers' educational and social class.
Source: Lucas, A., "Breast Milk and Subsequent Intelligence Quotient in Children Born Preterm". Lancet 1992;339:261-62.
b. Cognitive Development Supplementary regression analysis examining the strength of relationship between duration of breastfeeding and cognitive development show a small but significant relationship between duration of breastfeeding and scores on the mental development index of the Bayley Scales at 1 and 2 years.
Source: Morrow-Tlucak, M. "Breast Feeding and Cognitive Development During the First 2 years of Life. "Soc Sci Med, 1988.
In 771 low-birth-weight infants, babies whose mothers chose to provide breastmilk had an 8-point advantage in mean Bayley's mental developmental index over infants of mothers choosing not to do so.
Source: Morley,R., "Mothers Choice to provide Breast Milk and Developmental Outcome." Arch Dis Child, 1988.
c. Social Development The psychomotor and social development of breastfed babies clearly differs from that of bottle-fed ones and leads at the age of 12 months to significant advantages of the psychomotor and social capabilities.
Source: Baumgartner, C., "Psychomotor and Social Development of Breast Fed and Bottle Fed babies During their First year of Life". Acta Paediatrica Hungarica, 1984.