Scientists at the University of Copenhagen said they asked two groups of workers to watch a video of people passing a ball back and forth.
One group was then allowed to watch a funny online clip, while the other team had to go straight to work.
Researchers found workers who watched the funny clip made fewer mistakes when asked to recall how many times the ball had been passed.
They concluded that banning workers from using the Internet freely will eventually make them less focused, motivated and effective.
