Some studies of successful language learners have suggested that they're more "open to new experiences" than the rest of us. Temptingly, psychologist Alexander Guiora proposed that we have a self that's bound up in our native language, a "language ego", which needs to be loose and more permeable to learn a new language. Those with more fluid ego boundaries, like children and people who have drunk some alcohol, are more willing to sound not like themselves, which means they have better accents in the new language.
Michael Erard, Babel No More: The Search for the World's Most Extraordinary Language Learners
accents, language, language-learning