Petitto’s findings are consistent with most recent research in the field of bilingualism. There is a good deal of support for the “critical period”: the theory that a child’s brain is best suited to learn a language effortlessly and perfectly during the early years. The brain loses this capacity around the onset of puberty (roughly 10-14 years old). Some researchers even claim that as early as the age of five some ability to absorb a new language begins to diminish.