脯乳(breast-feeding)的小孩更聰明、好學，事業更成功

此段說明有可能有小矛盾，即富家更傾向脯乳，而富家子女更容易成功....非脯乳之功-----這只是我的猜測。

There is more evidence that breast-feeding babies changes their lives for the better. According to a new study, the benefits of having been breast-fed include: four extra points of IQ, an extra year’s education and a significantly enhanced income at the age of 30. It contradicts the suggestion that social class is a confounding variable, with rich mothers tending to breast-feed more than poor mothers do http://econ.st/1I4FlQ8