Alice Robb:
It’s surprising, though, that people who are actually fluent in two languages also feel their personality shifting as they switch between languages. Yet researchers have confirmed this: Between 2001 and 2003, linguists Jean-Marc Dewaele and Aneta Pavlenko asked over a thousand bilinguals whether they “feel like a different person” when they speak different langauges. Nearly two-thirds said they did.
My English self is definitely different from my German one.