Even infants are now watching screens, and as they grow so does the time they spend doing it, two new studies show.
In fact, watching TVs, computers, smartphones, tablets or electronic games occupies about an hour a day of an infant's time and increases to more than 150 minutes by age 3. That's way beyond what's recommended, the researchers said.
"Since screen-time exposure starts so early, it is important to continue to understand what factors play a role in forming screen-time habits," said lead researcher Edwina Yeung. She's an investigator in the epidemiology branch of the U.S. National Institute of Child Health and Human Development.
"While the type of child care is not always modifiable, the awareness of its impact may help parents try new ways to restrict exposure, either from discussing screen use with caretakers or with using technologies to track the screen time," she said.
Yeung and her colleagues collected data on the mothers of nearly 4,000 children who answered questions about their child's media habits from the ages of 1 to 8.
The American Academy of Pediatrics advises that kids under 18 months of age shouldn't be exposed to screens at all.
At 18 to 24 months, screen time should be introduced gradually and limited to an hour a day for children aged 2 to 5, the guidelines suggest.
Yeung's team found, however, that 87% of kids were glued to screens for far longer.
As kids reached ages 7 and 8, screen time declined to about 90 minutes per day. The decline was most likely due to school activities, Yeung speculated.
Differences did occur between children. Screen time for about 73% of the kids increased from about an hour a day to nearly 2 hours. For some 27% of the children, however, screen time rose from about 30 minutes a day to about 4 hours.
More screen time was tied to lower levels of parental education. Also, girls were a little less likely to use screens than boys. But kids of first-time moms were more likely to use media a lot, the findings showed.
Kids kept at home rather than put in day care were more than twice as likely to have lots of screen time, the study authors noted.
Reshma Naidoo, director of cognitive neuroscience at Nicklaus Children's Hospital in Miami, agreed that infants should not be exposed to screens in the first 18 months of life.
"The two-dimensional images on screens are very restrictive," she said. "Also, screens offer a lot more spontaneous reinforcement, so patience doesn't develop and anticipation is decreased."
But Naidoo thinks that screens are and will continue to be a bigger part of children's lives.
"We need to change the conversation from limiting screen time and being concerned that we're spending so much time on screens to what do we do with that screen time," she said.
"How do we turn it into something more meaningful? Because the entire world has shifted to a more digital environment," Naidoo said.
To that end, she thinks that guidelines are needed that help parents integrate media into their kids' lives.
It's not only helping parents know which programs are best, but also what activities they can do with their child after watching a program or playing a game.
In the second study, Canadian researchers found that about 79% of 2-year-olds and nearly 95% of 3-year-olds spent more time on screens than recommended.
Kids of moms who spent lots of time with screens also watched more media, as did kids who were kept home and not put in day care, the study found.
For this study, researchers collected data on nearly 1,600 2-year-olds and 2,000 3-year-olds.
These findings are concerning, said lead researcher Sheri Madigan, an associate professor of psychology at the University of Calgary.
"Research shows that excessive screen time in preschoolers may be problematic for their development," Madigan said. Parents should be aware of the guidelines and find ways to limit screen time, she added.
Another expert said the home environment also plays a role.
"The context of the viewing plays a very important role," said Dafna Lemish, a professor of journalism and media studies in the School of Communication and Information at Rutgers, the State University of New Jersey.
"Children's media time is impacted by having siblings around them, or by their parents' own media use," Lemish said.
If the household has a TV playing in the background nonstop, the child is growing up in a very different environment and learns very different lessons about how to use media than the child growing up in a family where the TV is turned on and off selectively, Lemish said.
In homes where parents have higher levels of education, kids are usually exposed to a more enriching environment, one that includes books, games, art activities, outings and enrichment programs that provide a host of competing and attractive ways for children to grow and develop, she said.
"Unfortunately, this is not the case for struggling families -- thus the popular criticizing parents for too much TV or gaming disregards structural inequalities in society more generally," Lemish said.
Both studies were published online Nov. 25 in JAMA Pediatrics.
For more on children and media, head to the American Academy of Pediatrics.