A recent study shows that bilingual people are able to switch tasks more quickly than monolinguals. This actually comes as no surprise. The ability to switch gears and refocus on another subject or task at hand seems an almost indispensable skill these days -- certainly in my world. What I find tragic is the fact that thousands, if not millions, of immigrants to the US, Britain, Australasia and other English-speaking countries ceased speaking their mother tongue with their children once they arrived on new shores. So many children of immigrants I've met are now monolingual because their parents wanted (them) to fit in in their new host culture. As a result, these children have been robbed not only of a valuable asset in today's world, bilingualism, but also much of the cultural heritage of their home country.
The good news is that it's not too late! Whether it's going back and relearning the old language or learning a new one, anyone can develop a second language that will benefit them in oh so many ways -- including the ability to multi-task!