第一胎为何更聪明？

First Children Are Smarter——but Why？

好多人都说父母的第一胎更聪明、更有成就。可原因究竟是什么？是因为他们继承了父母最好的基因？抑或是他们得到了父母最好的照顾，7读读下面这篇文章吧，你会找到满意的答案!

＂Those born earlier perform better in school＂--and according to a new study, it＇s because of the parents.