Technology writer David Pogue, who finds the evidence about teens and smartphones to be mixed, mentions a fact worth noting in Scientific American’s new e-book, Your Brain in the Smartphone Age,

There is, however, early research out— and it provides some insight into how these suddenly ubiquitous gadgets might be affecting kids. One study, published in the February 2015 issue of Pediatrics, found that children who sleep near a small screen get an average of 21 fewer minutes of sleep than kids without gadgets in their rooms. (As for the reason: the researchers suppose that kids are staying up late to use their gadgets, or maybe light from the screen produces “delays in circadian rhythm.”)

David Pogue, “The Touch Screen Generation” at Your Brain in the Smartphone Age

The paper he refers to is open access:

RESULTS: Children who slept near a small screen (compared with never) reported 20.6 fewer minutes of sleep (95% confidence interval [CI], −29.7 to −11.4) and had a higher prevalence of perceived insufficient rest or sleep (prevalence ratio, 1.39; 95% CI, 1.21 to 1.60). Children who slept in a room with a TV (compared with no TV) reported 18.0 fewer minutes of sleep (95% CI, −27.9 to −8.1). TV or DVD viewing and video or computer game playing were associated with both sleep outcomes (P < .01). Some associations were stronger among Hispanic, non-Hispanic black, and older children (P < .05 for heterogeneity). – Jennifer Falbe, Kirsten K. Davison, Rebecca L. Franckle, Claudia Ganter, Steven L. Gortmaker, Lauren Smith, Thomas Land, Elsie M. Taveras Sleep Duration, Restfulness, and Screens in the Sleep Environment Pediatrics February 2015, VOLUME 135 / ISSUE 2

Many sources say that sleep is very important for children. If sleep is lost, what will make up for it?

See also: Scientific American: No Consensus on Smartphones’ Effect on Teen Brains Others continue to wonder why teens seem comparatively fragile The editor’s view is that “change is unceasing, and different does not necessarily mean worse – despite the fears of the “cluck-cluckers.” We recommend several other sources for alternative context and background.

and

Smartphone 10 Conversation 0