Mothers who breastfeed their babies for longer than six months, breed smarter children, as it improves their brains, a benefit lasting well into their school years and particularly important for boys.

The Telethon Institute for Child Health Research study published in the journal Paediatrics found 10 year olds breastfed for longer than six months as infants, significantly achieved higher academic scores than those breastfed for less than six months.

Researchers collected data for the study from 1038 children all aged 10 years, then adjusting such data for gender, family income and maternal verbal interaction.

Breastfed boys were found to have improved academic scores in standardized math, reading, writing, and spelling tests, while girls breast fed for the same time frame showed a small improvement in reading.

However, when researchers adjusted their findings keeping other factors associated with breastfeeding having a possible influence on academic achievement, such as, the mother’s age, family income, how often children were read to at home, the advantage continued to be seen only in breastfed boys.

Calling its conclusions misleading, the study’s critics say mothers opting for breastfeeding tend to be typically older, have higher IQs higher, are better educated and wealthier, than mothers who do not.

This makes it difficult for researchers to determine whether breast feeding or having greater socio-economic advantages is responsible for breastfed kids performing better on intelligence tests.

Study co-author Associate Professor Wendy Oddy says the findings prove there are benefits to breastfeeding longer, as there are vital nutrients in breast milk that support brain development.

The positive effect breastfeeding has on mother-child bonding is important for boys, as they are more dependent on maternal attention for developing cognitive and language skills. Breast-feeding is known to improve speech clarity particularly for boys, with better speech associated with improved reading ability. As well, breast-fed boys tend to mature more quickly, whereas normally they lag behind girls in development, or else hormonal differences might be at play.