Amit Bhargava for The New York Times

“Being bilingual, it turns out, makes you smarter,” Yudhijit Bhattacharjee writes in an op-ed in The New York Times. “It can have a profound effect on your brain, improving cognitive skills not related to language and even shielding against dementia in old age.”

But if being bilingual is good, what about being trilingual, as so many people in India are? Or even quadrilingual?

That’s hardly unusual in India, where someone may, speak, say, Punjabi and Hindi with their father’s family, Bengali with their mother’s and Hindi and English with their spouse and children. India’s 2001 census lists 122 languages, and bi- or trilingualism is so assumed that the census questionnaires ask respondents for their first, second and third languages.

Almost 20 percent of India’s population, some 240 million people, is multilingual, and millions are trilingual. (Sri Lanka, meanwhile, has proclaimed 2012 the “Year for a Trilingual Sri Lanka.”)

But research into the effect of trilingualism is scarce, in India or worldwide.

“Trilingualism is generally treated in the relevant literature as another type of bilingualism, and theories and findings from studies of bilinguals are often assumed to be applicable to trilinguals by extension,” Suzanne Barron-Hauwaert, a researcher on languages wrote in 2000. A study Ms. Barron-Hauwaert conducted on trilingual children, mostly in Europe, found that three languages can’t be balanced as easily as two, and that a child’s age plays a big part on what language it would speak. She found “very young children using the mother’s language as their first language while 3- to 4-year olds use the father’s language; the older children prefer the local language.”

In India, research on the dozens of languages spoken in the country often has an economic focus, rather than any focus on the effect on individual intelligence.

Analysis of Indian multilingualism during the 19th and 20th centuries looked at it as a “problem” to be overcome, according to a research paper published on the Evaluations and Language Resources Distribution Agency Website. “But, in the present 21st century, because of the systematic language policy initiatives of the past half a century, we have begun to look at multilingualism as an asset.”

In a 2008 study focused on India, an economics professor said “language learning and linguistic diversity ought to be taken as endogenous to the process of economic development.”

Do you speak three or four languages? If so, what are they, and how do you think it has affected you?