"Tie the first smartphone to the driver's license Twenge spent years giving vague answers when parents asked what age a child should get a smartphone, until she realized that "it depends" is unworkable advice against relentless preteen lobbying. Her solution: make the rule external and unambiguous — "if you do like we ended up doing in my house, you get your first smartphone with your driver's license, then that's it, it's a line in the sand, it's done." This also removes the false trade-off where a teen without a phone or car defaults to Snapchat instead of real-world socializing, and it gives reluctant teens a genuine reason to pursue their license. Source: Jean Twenge, The Happiness Lab, Social Media and Teen Mental Health"