CAN WE SWAP OUT THE NATIVES?:

Kelin Funes, a senior at Boston International High school, poses for a portrait at school. An honors student and former English learner, Funes will attend UMass Lowell in the fall, with hopes for a career in biotechnology.ERIN CLARK/GLOBE STAFF

The familiar tale about English language learners emphasizes failure: they lag behind other students, drop out at higher rates, and are less likely to pass standardized exams.

But there is a lesser-known flip side to that story, one that advocates are working harder to promote: Former English learners -- students who were once ELs, and shed that status when they mastered English -- often emerge as high achievers, matching or surpassing their peers' performance in school and on standardized tests, including the Massachusetts Comprehensive Assessment System, or MCAS.

Researchers haven't pinpointed the reasons for the higher scores of former English learners on some standardized exams, and they say answers may prove elusive, because test-taking is such a complex task. But a robust body of scientific data has established some brain benefits of bilinguality: Those who regularly use more than one language increase the density of cells that process information, and strengthen their brains' executive control network, used in cognitive tasks requiring focused attention.

Tweet   @brothersjudd