[jjacobson]

My brother learned Cantonese fluently as a LDS Missionary. He then enlisted in the army after 9/11 and was given a battery of aptitude tests. I'm assuming this was one of them because he ended up at DLI learning Arabic and speaking that fluently as well.

DLI and being a Mormon missionary are about the two best places you can learn to speak a 2nd language fluently in a short amount of time.

[vorg]

> Before the participants took the half-day long tests they’d been sorted according to how well they knew a second language

Does doing well in the tests reflect how well someone will learn a second language, or does having already learnt a foreign language (e.g Cantonese) affect how well someone will learn another (e.g. Arabic) ? It could all be a mixup of causation and correlation!