I thought this was fascinating from Joanne Jacobs:

Every year, the San Jose Mercury News runs photos and a profile of the valedictorians of local high schools. I'd guess the majority come from immigrant families, mostly Chinese, Vietnamese, Indian, Iranian and Russian. It's rare to see a Spanish name. Here's the most recent "best and brightest" page. (It takes all summer to do all the schools, many of which have multiple valedictorians.) The names are: Hsu, Bhople, May, Lin, Lai, Tran, Allen and Doan. Maybe not representative. Let's try another one: Slagle, Lee, Zhang, Gottipatti, Harper, Avila, Claus, Dao, Jebens, Koval, Johnson, Kapulkin, Sato, Jhatakia, Decena, Ashe, Tran, Nguyen, Pham, Dick.

Theorem:  Immigration is hard and requires gumption.  Children of gumptious parents (yes, gumptious is the adjective) will also display that trait and devote themselves to their studies.  So more of them will become valedictorians.

See Thomas Sowell FMI.