What unites all these recommendations is a call for more, higher quality research. We still know so little about how screen time impacts anyone, much less young children, and what data we do have is mostly correlational. That prompts organizations like the WHO to take a cautious approach. In the report, they note that even though the evidence for the harms of screen time is quite low, there's excellent evidence that engaging more in other behaviors—like being physically active and sleeping—will help your kids. And in light of that, they're going to recommend less screen time in favor or more exercise and rest. There are only so many leisure hours in the day, after all.