Setting and maintaining reasonable boundaries around technology is now a fundamental part of parenting. Of paramount importance: when to give a kid their very own device.

This isn't something to be taken lightly. Analytics firm Flurry says American consumers spend 5 hours a day on our mobile devices. Another study said time spent in mobile apps increased a whopping 69 percent year-over-year.

Considering how many hours a day this budding human brain will spend staring at that screen, it's worth putting serious thought into what age is appropriate to get a mobile device.

According to the latest research, on average, a child gets his or her first smartphone at 10.3 years old. That same study shows that by age 12, a full 50 percent of children have social media accounts (primarily Facebook and Instagram).

Not so with the Gates family. In a recent interview with The Mirror, Bill Gates said he didn't let any of his children get their own phone until they were 14 years old.

That's right: His kids, now 20, 17, and 14, weren't allowed to have smart phones until they were high school age.

Gates is joined in this assessment by James Steyer, CEO of Common Sense Media, a nonprofit that reviews products and content for families. In the Steyer household, kids have to be in high school before they can get a phone -- after demonstrating they can exercise restraint and understand "the value of face-to-face communication."

On other parents facing the same choice, Steyer says, "No two kids are the same, and there's no magic number ... A kid's age is not as important as his or her own responsibility or maturity level."

If you're looking for a way to evaluate that maturity level, PBS Parents has curated a list of practical questions to ask yourself before giving a child their first cell phone. They include things like:

  • Do your children "need" to be in touch for safety reasons--or social ones?
  • Can they get behind the concept of limits for minutes talked and apps downloaded?
  • Can they be trusted not to text during class, disturb others with their conversations, and to use the text, photo, and video functions responsibly (and not to embarrass or harass others)?

It's worth noting that even after cell phones have been distributed, the Gates family still limits screen time. Mobile devices are banned at the dinner table (this goes for kids and parents alike). For younger kids, overall screen time is even more limited: "We often set a time after which there is no screen time, and in their case that helps [the kids] get to sleep at a reasonable hour."

Perhaps unsurprisingly, there's something else strictly banned in the Gates household: all Apple products.

Apparently whatever smartphones the Gates kids have, they're not iPhones.