> Being bilingual is just another proxy for a middle class or higher upbringing.

... or you could be raised by immigrants who continue to speak their mother tongue at home while the children learn English (or whatever else is the primary language) via TV/School/Public. There's nothing higher upbringing about retaining your parents' culture. If anything, it's more associated with lower class families.

Amongst immigrant families, yes. It's different with groups that have been here several generations.

...but if you're going to say that selecting for bilingualism is actually selecting for affluence, you can't ignore a huge population that is bilingual and not affluent.

How do you figure? In the US, at least, there are lots of poor immigrants and lots of well-off people raised in English-speaking households. The only reason I can think of which would correlate with wealth would be language classes in school, but most bilingual people get it from being raised that way, not learning it later on. And I believe this article is only discussing bilingualism achieved by being raised with multiple languages, not learning them in school.

Good schools push children into actually learning a second language. The poorer schools around here don't offer as much of an emphasis on foreign languages.

I didn't see a reference in the article about acquiring a second language via upbringing and through other means.

How many of those children pushed into learning a second language actually learn it to the point of fluency? In my experience, that number is nearly zero. For every student who attains fluency from school, there are dozens who don't.

I'm having a hard time figuring out exactly how they selected people in the various studies referenced in the article, but the lack of any reference to native versus non-native languages indicates to me that they're looking at people who speak multiple languages natively. Many of the referenced studies are about young children, who simply wouldn't have had time to learn a language to fluency in school.

Does anyone ever achieve fluency in school? I seriously doubt it. I studied German for four years in high school, and I am most certainly not fluent. AFAICT, you really have to be immersed in the language for some time to become truly fluent in it. Studying it in a classroom with only one single fluent person (the teacher) to talk to is not going to do it.

Probably not. Well-off people can better afford study-abroad programs and other such things which could potentially take you from a foundation learned in school to fluency, so that would still be a potential link. Still, the number of people who pull that off has to be small compared to those who just grow up in a bilingual (or just non-English-speaking) household.

I believe that's almost completely false.

My wife was raised in a country where one language was spoken in the house, but she was taught at school in a completely different language. Absolutely nothing to do with being middle class or having a higher upbringing. It was mandated by the State that she be taught in one language, but they couldn't force a local population to completely change their mother tongue in the home and in private.

There are many other situations I can imagine, and know of first hand, where people of all socio-economic levels speak more than one language.

The only time I can think bilingualism may be such a proxy is in a largely mono-linguistic culture.

Depends a lot on where you live. Live in a lower class Hispanic neighborhood? Both English and Spanish would be pretty essential.

So, in the US studying a second language is necissary for high school graduation.