Theo Rowland-Fry's parents probably weren't thinking about doughnuts when they bought their iPad.
Yet in March, doughnuts were very much on their mind: They discovered their 8-year-old son, Theo, had racked up a tab of more than $1,500 for virtual doughnuts in the game "Simpsons: Tapped Out."
Though the Rowland-Fry's case may be extreme, excessive gaming is not unusual. As smartphones and iPads become ubiquitous, more parents are dealing with the fallout of ever-present mobile gaming, ranging from overspending on mobile apps to children who are crazed for "Candy Crush Saga."
Mobile technology can be a lifesaver for overworked parents looking for a little down time, but such portable entertainment can also become an irresistible lure for some kids. As a result, kids' schoolwork, sleep and physical activity can suffer, say scientists who study the effects of gaming on children. And for particularly shy kids, these games may act as a substitute for in-person social interaction. The games can even keep children from learning a vital skill: how to do nothing.
Despite the hype, however, mobile gaming isn't a problem for many children, and many games actually offer benefits. Tons of apps and games are educational, said Patrick Markey, a psychology professor at Villanova University in Pennsylvania. [The 10 Best Science Apps for Your iPhone]
And many children can happily play for an hour or two and buckle down on schoolwork afterward.
Many games also have a strong social component.
"With games like 'Minecraft,' even when kids or adults are playing by themselves, they're not alone," Markey said.
Still, children may be more vulnerable than adults to the lure of mobile games.
"Games can be addictive," said Ofir Turel, an information and decision scientist at California State University, Fullerton, and a visiting professor at the University of Southern California. "Anything that provides the brain a reward has the potential to become addictive." [7 Clever Ways to Get Kids to Put Down the iPad ]
Because the inhibitory portions of children's brains aren't fully developed, it may be harder for kids to shut down their impulse to play, Turel told LiveScience. The ensuing screaming and tantrums when an iPad or other mobile device is taken away give sure signs of this lack of self-control.
Gaming becomes a problem if it interferes with other aspects of children's lives, including their grades, social activity and even their sleep.
For instance, if a child's grades slip because playing "Candy Crush Saga" interferes with doing homework, then that's a problem. If kids spend too much money in online games, that may also be a problem, experts say.
Kids may also stay up late playing games, and spending time in front of a bright light can disrupt a person's circadian rhythms. These disruptions can delay sleep and make it hard for youngsters to fall asleep once they finally do put down the iPad. Violent games may interrupt sleep when kids finally do drift off, Turel said.
Beyond interrupting school and other daily activities, being tired can increase hunger, which may lead to overeating and weight gain, studies have shown, Turel said.
Turel's group has also shown that excessive gaming can crowd out physical activity. Children who play mobile games tend to be more sedentary, which may lead to weight gain and high blood pressure, he said.
Beyond the physical consequences, too much gaming may also inhibit proper social interactions. Shy or introverted people may retreat to games for friendship and camaraderie from online chatting. Though such online gaming allows introverts to make friends and feel connected on their own terms, it can also prevent these individuals from learning valuable in-person social skills, Markey said.
He has found that violent video games can be problematic for some kids.
"Kids who are really moody and unfriendly — not very nice children — their negative aspects tend to become magnified when they play violent video games," Markey said.
Games may also interfere with children's ability to learn essential, but mundane life skills, said Catherine Steiner-Adair, a clinical psychologist and the author of "The Big Disconnect, Protecting Childhood and Family Relationships in the Digital Age," (Harper, 2013).
"Kids start to use gaming when they're bored, when they're standing online, when they're frustrated," Adair said. "The problem with this is that they don't learn how to soothe themselves, calm themselves or entertain themselves in a quiet way."
Still, mobile games aren't necessarily a problem in and of themselves.
The trick is finding balance. Kids should enjoy games, but not to the exclusion of other fun and necessary activities.
"If you say, 'Oh, let's play miniature golf,' and they get upset, then you probably have a problem," Markey said.
Rowland-Fry's parents are still struggling to find that balance. For now, Theo's iPad is now safely tucked away in a drawer.
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Tia is the managing editor and was previously a senior writer for Live Science. Her work has appeared in Scientific American, Wired.com and other outlets. She holds a master's degree in bioengineering from the University of Washington, a graduate certificate in science writing from UC Santa Cruz and a bachelor's degree in mechanical engineering from the University of Texas at Austin. Tia was part of a team at the Milwaukee Journal Sentinel that published the Empty Cradles series on preterm births, which won multiple awards, including the 2012 Casey Medal for Meritorious Journalism.