老大照書養，老二照豬養，老大往往將來更成功一些。

"In her research, Black has found that first-born children tend to do better than their younger siblings when it comes to education and earnings. After the first-born, there’s a declining pattern by birth order, with the second-born doing “a little bit worse than the first-born” and so on, she says. "

https://www.marketplace.org/2018/07/18/economics-birth-order-reflect-your-own-experience/