Chance are high that your read these lines on a smartphone. Maybe your were even alerted by a push notification. Researchers Adrian F. Ward, Kristen Duke, Ayelet Gneezy, and Maarten W. Bos invesigated the effects of having the smartphone nearby. The results are striking: the closer your smartphone is, the bigger the effect on your mental capabilities. The effect is small but statistically significant — on par with effects of lacking sleep.
If you want to work at your best productivity level simply put your smartphone away and out of sight. This needs some planing but your productivity will thank you.