请看别人的研究结果，2万个美国婴儿的调查，他们的结论与你相悖。

顺带说一句，我自己也是受网友启示（非常非常感谢），刚刚找到这个报道。

Baby's sleep position is the major factor in 'flat-headedness'
link:
http://www.sciencedaily.com/releases/2009/11/091119101211.htm

“Analyzing the largest database to date, more than 20,000 children, the ASU researchers found that the number of babies who have developed flat-headedness has dramatically increased since 1992. The increase coincides with the American Academy of Pediatrics launch of a "Back to Sleep" educational campaign that recommended parents place their infants on their backs to reduce the risk of Sudden Infant Death Syndrome.”