People who were breast-fed as babies are more likely to climb the social ladder in adulthood, compared to those who were bottle-fed, British research finds.

Researchers at the University of Bristol analyzed data on more than 1,400 people from 16 rural and urban areas in England and Scotland who were born from 1937 to 1939. Among these people, the likelihood of being breast-fed was not dependent on household income, spending on food, birth order, number of siblings, or social class in childhood.

The study found that individuals who were breast-fed as babies were 41 percent more likely to advance up the social ladder than those who'd been bottle-fed. The longer a person was breast-fed, the more likely they were to be upwardly mobile.

The potential benefits of breast-feeding on brain development may lead to better exam results, job prospects, and greater earning potential, the study authors suggested.

There may also be other, as yet unknown, social and economic factors associated with breast-feeding, the researchers added. They also noted that breast-feeding may improve long-term health, which is associated with socioeconomic factors.

The study is in the current issue of the Archives of Disease in Childhood.