Gregory K. Moffatt, Ph.D.
Since I first started this column in 1994, I have written several times about the amount of time children spend in front of the television and/or the computer. The data in the old days was largely based on TV time with some studies looking at computer screen time. In those days, it appeared that excessive time in front of the TV or playing video games created a host of troubles in developing children.
Who could have known back then where we would be today. A lot has changed. In those days, in order to have "screen time," children had to be in the house in a specific room where a computer or the television was. Video players in cars existed, but were fairly uncommon. Otherwise, "screens" were heavy, immobile objects in a den or office.
Today, we have had to totally re-define what we even mean by screen time. This still includes televisions and computers, but also phones, tablets, laptops, e-readers, and other portable digital devices. These devices are almost exclusively portable and be used for almost anything - movies, television, games, communications, etc., and children are spending more and more time in front of them.
For example, a recent study published in the Journal of the American Medical Association (JAMA) showed that the average number of hours that children under two spend in front of a digital screen went from 1.32 hours in 1997 to 3.05 hours in 2014. And The US National Library of Medicine puts forth that children, on average, spend over five hours a day in front of some device.
These devices have also changed us as adults. In the years before cell phones, before class and on breaks, my students would talk to each other.
Now, while my students are waiting on class to start, by far the majority are looking at their phones and the moment I dismiss class, they immediately drop their heads to look at their phones. This change has frustrated me and it isn't just college students. I even see it in restaurants - whole families with their heads down, each looking at their own device as if there was no one else around them.
Therefore, we have to ask very different questions today than we did in 1994 and we can't assume that data derived from studies in the 80s and early 90s are applicable to the devices we have today.
So here is what we know so far. While there are a few studies out there that indicate screen time has almost no effect on children (see Nature Human Behavior 2018), those studies are rare and those studies look at "children" as anyone under 18 years of age. Developmental stages matters.
The American Academy of Pediatrics stated in 2014 that children under 18 months of age should have zero screen time. The developing wiring in their brains, known as synapses, are proliferating and this "plasticity" or pliability makes them vulnerable to damaging effects that doesn't apply to older children.
A National Institute of Health study shows changes in children's brains if they consume more than two hours a day of screen time. This study also showed these children have lower scores on language measures. In a similar tone, the 2019 JAMA study showed that excessive screen time is associated with language delays, social delays, obesity, and a general delay "in meeting developmental milestones at ages 3 and 5."
Obviously, not all screens are the same. I would be delighted for children to spend an hour or two reading a Kindle. There is not much difference between a Kindle and a paper book in terms of its effects.
And, as I've always said, not all programming is the same. Interactive and engaging programming (e.g. educational programming) is superior to passive viewing (cartoons).
You can limit the negative effects of screen time by limiting the hours on these devices. Like almost everything, screen time is not inherently bad, but in all things moderation. So don't be tempted to use the mobile device as a portable babysitter. And perhaps we could start with being good models ourselves. Have a "no device" period of the day or a day of the week with no digital media. No texting in the car or no phones at the dinner table is another idea.
These sensible limits might allow us to enjoy and take advantage amazing digital technology and at the same time moderate their potential negative effects.