Via Business Insider:
You might not be a Jane Austen or a Herman Melville even at the best of times, but if you want to be a much better writer, you need to limit distractions. “Try to reduce external interruptions as best you can,” Foroughi told New Republic. “Turn off your cell phone. Turn off your Twitter and email notifications. You can live without them for an hour or two.”
Here’s An Easy Way To Massively Improve Your Writing – Business Insider
The result of some doctoral research. This is also why writers are encouraged to have a separate room where they can close the door.