One of the things immigration advocates always say these days when talking about comprehensive reform is that as part of a path to citizenship, we should "make them learn English." This is pretty good as a policy matter, since knowing English is only going to be a help to any immigrant, and the more smoothly immigrants can be woven into the economic and social fabric of the country, the better. But it's also driven by a political calculation -- "make them learn English" polls very well, and the reason is that a lot of the unease people have about immigrants comes from language differences (the tone of it also makes it seem like we're being punitive, or at least kicking them in the butt a little, which people like). One of the things you hear from opponents of immigration, on the other hand, is that today's immigrants "refuse to learn English" as they dilute our society with their foreign ways and foreign tongues.
But is that really true? Via Sociological Images, sociologist Claude Fischer gives us this interesting graph showing how quickly immigrants of different waves learned English:

The evidence is pretty clear: If anything, today's immigrants acquire English skills faster than those from the days where men wore hats and everyone was painted in sepia. And that doesn't cover the generational angle, which is that every wave of immigrants goes through roughly the same linguistic pattern. The people who immigrated as adults learn something of the language, but don't usually become fluent; their kids are bilingual; and their kids are much more comfortable in English. As usual, when you look at today's immigration questions in the context of our prior history, it doesn't seem so unusual or threatening.
-- Paul Waldman