Read more about a study in Being bilingual alters your brain. Here’s how at https://www.weforum.org/agenda/2016/02/how-being-bilingual-rewires-your-brain/?utm_content=buffer4f1ad&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer. Excerpt:
Kroll told Quartz this study is a great example of how being bilingual can improve speakers’ cognitive abilities. “Babies who are listening to two languages [growing up] become attuned to those two languages right away,” said Kroll. “It’s not confusing them or messing them up developmentally—the opposite is true.”
This rewiring doesn’t happen the same way in every bilingual brain—it’s different for each person, just as each person has their own language experience. But Kroll’s research demonstrates that no matter how effortlessly other bilinguals may seem to switch between their two tongues, there’s a lot going on under the hood. That should come as a small relief for anyone attempting to pick up a new language.