My daughter has some friends-A, B, C and D.  Three of them are single chid.    

A, single child- her family are very active outside sports-hiking, boating, and sking.

B. Single China Child, born in USA ( tiger parents)-  her family is very proctective her, so she lacks social skill compared to other kids.  Her academic is on the top 3 of classroom. 

C. Single Child- her dad died when she is 3 yr old, her mother has boyfriend live with them.  She has a lof of pets at home.

D. her parents divorced, she lives with her mother and stepfather during weekday and live with her dad at weekend.   Her mother has 2 more kids with her stepfather and her dad has one child with her stepmother.  So she has 3 half borther and sister.

Compared to my son's friends- X, Y, Z they have normal family and with more than one sibling. 

X. younger child has two college brothers & sisteres.  His parents work at hospital, he is smart and has idea to group kids together for some activies.

Y-eldest child, with two younger sisters.- His family is very religion, he doesn't attend any after school programs from middle and high schools.  all he does is study at home and take care a dog.

Z-eldest China child- skip grade in other state, move here at 3rd grade. He is younger than the same grade kids.   He is doing OK at school, but didn't meet what his mother's expectation.  his mom has PHD degree in China, but has hard time to find a job in USA.

Personally, I don't like my kids has close friends with China or Taiwan. Because competition at the same grade, sometimes parents are very sensative at who can go to spelling bee  or who can skip garde at the maths, etc.     You wins, the other party won't be happy.   You lose, you won't be happy for while either.   

I told my kids Forrest Gun story ( Tomas Hank), keeping going and disregard what other parent's gossip, then  you will get what you want.  Be happy.