Fourth, higher quality maternal interactions have been shown to
improve brain development at 5, 10
and 24 months.34 Fifth, there is growing evidence to suggest that the beneficial effects of exclusive breastfeeding may be moderated by the infant's genome, 35,36
and the metabolism of the fatty acids in maternal breast milk.37 For example, Krol et al. 36 showed that infants exclusively breastfed for a longer duration (above the 50th percentile) showed a heightened sensitivity
and interest in a happy visual stimulus (
eyes) than infants exclusively breastfed for a shorter duration (below the 50th percentile).