[jaredklewis]

I too often read about research that suggests children are better at learning languages than adults, which may or not be true, but I am rarely convinced by these reports. Finding a correlation between the age a person started learning a language and their fluency, the reports then conclude that children are superior learners, without considering other factors like that bi-lingual children are exposed to their languages constantly and must learn them to communicate with others, while adult learners find 2 hours of study onerous and suffer few if any consequences from not learning.

Other studies are more scientifically rigorous, testing the aptitude of various language learning abilities with quizzes and games, but I think we can infer very little about the efficiency of long term studying from these narrow tests.

Just anecdotally, I live in Japan, and most foreigners I know who come as adults and work in a Japanese environment are conversational in a year, fluent in 3 or 4.