But those studies were flawed because they relied on the change in the baby's facial expression upon receiving the sugar, from puckered-up to relaxed, as proof that it works, the new study says.

新研究评述道，这些研究其实是存在缺陷的，因为他们是依据婴儿在喂糖之后面部表情由皱着脸蛋变为放松来作为有效的证明。