I said I wouldn't get my son a cellphone. I changed my mind when he turned 11, and I'm glad I did.

• Over the course of my career, I've learned a lot about the dangerous effects of cellphones on kids.
• So, I swore I'd never get my kid one, but when he was 11, I finally gave in.
• So far, it's been going well, and he seems to be handling it responsibly.

As a parenting and health writer, I've spent way too much time reporting on the extensive mental health concerns around phone use. Therefore, I always thought I would be the very last person to ever buy my kid a phone, let alone at 11 years old. I was sure my kid would be starting high school phone-free

I know recent studies show protecting our kids' growing minds is our top priority as parents, and research shows that kids who use smartphones have poorer mental health outcomes. I also know about all the warnings — from social media's impact on self-esteem to the effects of blue light on sleep.

Along the way, though, amid all the convincing research, horror stories, and warnings, I forgot one essential parenting lesson: I am the expert on my own child, and every child is different.

This means that the perfect age to get them a phone varies, just like the perfect age for their first bike, or first solo trip to see a friend in the neighborhood. When I bought him a phone, I was surprised that it made life better, not worse.

My son started asking for a phone early

My son started asking for a phone earlier than I'd expected — around 9. He started telling me that "everyone" in his class and friend group had one. I was prepared for his hyperbolic language and ready to stand my ground.

I helped him communicate with his peers through "workarounds," such as using his iPad and Messenger Kids to talk to friends, texting their parents more often to organize in-person hangouts, and letting him use my phone to look things up while supervised. We'd struggle when he was running around the neighborhood with his friends, since he'd use their phones to keep me updated.

As someone who has always loved knowing the plan, the ambiguous answers I gave when he asked when he'd get a phone started to become emotionally stressful for my son. I wasn't ready to put a date on it, but I could tell it was becoming a major source of anxiety for him.

I watched his defeated expression in the rearview mirror while his friends in the sports carpool played music and took silly pictures of each other. And I learned that when he got his first real crush, not having a phone was a major social disadvantage for him. It even started to hurt his self-esteem and confidence around his peers.

I made the decision to let him have a cellphone, with one rule

As my son's 11th birthday approached, I could tell his anxiety was running high about the topic that if we did not get him a phone, it would be truly crushing. This sounds dramatic, and like he runs the show, but it had become so important to him that it was true.

I had a decision to make, weighing the terrifying research that kept me up at night, convinced he'd get depression from owning a smartphone, and his desire to be a part of a group and communicate with his friends.

Separating the social media decision from the phone decision was helpful. Much of the research focuses on the damaging aspects of social media rather than on calling and texting friends, which is what he really wanted to do. Social media will remain a hard no for years. Outside of that, it was time to say yes.

During my son's birthday party, we heard an unfamiliar phone ring. It was his new phone, buried at the bottom of a bag of gifts. At first, he was confused, looking around for it, but then he slowly realized what was ringing. He had actual tears in his eyes opening it, thanking us repeatedly. I enjoyed the rewarding parenting moment of giving a gift he really loved.

He spent some time (not a ton, surprisingly) over the next few weeks conversing with his friends in regular, supervised text conversations.

It's been surprisingly uneventful since he's had his phone

I waited for the other shoe to drop, and maybe it still will. But it hasn't. In fact, his life and ours have improved since buying the phone. He seems to have matured, leveling up to the responsibility he's been entrusted with.

My extensive research, careful oversight, and training on the whole adage "with privilege comes responsibility" have helped.

He has already learned valuable, age-appropriate lessons about time and screen management. He's taken hilarious videos of his toddler sister.

I learned it doesn't have to all be the worst-case scenario, and that I truly know my own kid. In my gut, I knew he could handle it, and that it would actually make our lives better. I can now communicate with him more easily, he can enjoy a bit more independence around the neighborhood since we can check in with each other whenever, and he is more connected to his friends.

I hope the phone dilemma is the reason that, in future big parenting decisions, I get out of the research and out of my head and ask: What's best for my child right now, and my family. The "right" answers are there.