When it comes to warnings about kids and smartphones, The Anxious Generation author Jonathan Haidt is determined to get the message out. The social psychologist sat down recently with Prince Harry to amplify his ideas about keeping kids mentally safe from technology. And he’s also teamed up with psychologist and parenting expert Becky Kennedy—a.k.a. Dr. Becky—to offer help for those who want to heed Haidt’s warnings but don’t know how.

“Jon and I are such natural complements,” Kennedy, mom to kids ages 7, 10, and 13, tells Fortune. Haidt, she says, has done an excellent job of laying out the problems with smartphones and social media in a way that’s resonating with parents—highlighting the shift for kids from play-based childhood to a phone-based childhood, and the ushering in of social isolation, disrupted sleep, diminished focus, and anxiety.

“But parents are saying, ‘Okay, well, what do I do about this scenario?’ I know, for me in life, having a problem named without a solution offered is frustrating,” she says. “I just feel anxious.”

That’s where Dr. Becky’s parenting company, Good Inside, comes in—to offer its free guide, “5 Strategies for Parents to Free the Anxious Generation.”

“I feel like [Haidt] has massively increased parents’ motivation to look for a solution, and the solution is nuanced,” Kennedy says. “It’s on the ground, and it’s concrete. It’s actionable.”

While her five points of advice for parents—know your job, maintain boundaries, allow yourself to change course, teach competence as an antidote to anxiety, and join forces with fellow parents to enact smartphone rules—are clear and well-explained in the guide, below are some useful takeaways with additional perspective from Fortune’s discussion with Dr. Becky.

Why it’s so hard to set boundaries

Parents having an increasingly difficult time setting boundaries, Kennedy believes, is the “core of the problem.” Here’s why: “The cost of not setting boundaries with our kids has never been higher—because now when you don’t set boundaries, it’s not like your kid gets an extra ice cream. They get TikTok at age 8.”

She believes boundary-setting has gotten harder for parents because of two main reasons, the first being, simply, that parenting in such a technologically tricky time is uncharted territory.

“I don’t think parenting has ever come naturally,” she says. “But the idea that parenting would be natural in a digital world with all of this stuff available to our kids is at best a joke—and at worst, a way to purposely make parents feel awful about themselves.” Though there are courses for useful skills like CPR, for example, there are none when it comes to setting boundaries in the digital age.

“So why would we expect ourselves to magically absorb that ability? It’s just not how any type of learning works,” she says.

Another reason it’s harder to set boundaries, she says, is the impact our phones have had on us as parents. That’s because the more we’re absorbed in our own phones, the more we ourselves are rewired for instant gratification—and the lower our tolerance for frustration becomes.

“When our kids whine, complain, push back—which always happens when we set a boundary—we are literally less tolerant of our kids’ pushback, because we have developed a higher expectation of gratification and ease because of our reliance on our digital devices,” Kennedy says.

So at the thought of saying no and dealing with whining, we think, “‘I’m going to have to tolerate their upset—or I could just go back and scroll something on my phone if I say yes,’” she explains. “We have lowered our own frustration tolerance as parents, so we have a harder time setting boundaries because of that. And I think that’s a part of the equation we have to really talk more about.”

That’s because it’s not going away, she says—and because no kid will ever respond by saying, “I feel so safe with you, you’re such an amazing parent. Thank you for making a decision for my long-term health.”

Dr. Becky also tells parents this: “If you can’t say no to a cupcake, you’re not going to be able to say no to TikTok.” And, she explains, when you can start to say no to a cupcake—or to a later bedtime or a new T-shirt—you then “build into your relationship with your kid [the idea of] setting boundaries and tolerating their feelings.”

Fast-forward 10 years, and if you didn’t do that, she warns, and you then say no to TikTok, it will be harder to start setting those boundaries. If you do start early, “it’s been built into the fabric of your relationship.”

Why it’s also not too late if you didn’t set boundaries early

Know that you’re “like most people” if you didn’t start putting your foot down early, Kennedy says. And step one to getting past that, she says, “is forgiving yourself.”

“We were not set up to do this,” she says. “And a mantra I say to myself often is: The right time to change is always right now. So your kid’s 13, your kid’s 18, whatever. After you really have forgiven yourself, what is the first step you can take to set boundaries that feels manageable?”

To build that boundary-setting muscle, Dr. Becky tells parents of teens, it’s best to not start with TikTok. “It’s just not realistic,” she says. Instead, start with no longer allowing your kid to sleep at night with their phone in their room.

“That, to me, is a nonnegotiable boundary,” she says. “And you can present it in a way that your kid knows—and this is key—that we have to set boundaries from a place of protection, not punishment. The same boundary from a mindset of protection will be received in a very different way than the same boundary set from a mindset of punishment.”

Punishment, she explains, sounds like this: “You can’t have your phone in your room anymore. This is ridiculous. You’re not sleeping, you’re not responsible. I can’t trust you.” It’s an approach that would prompt rebellion and anger.

Protection, meanwhile, sounds like this, she says: “We’re on the same team, and one of my jobs is to prioritize your safety over your immediate, short-term comfort and happiness. We’re going to slowly make some changes. They’re probably going to feel uncomfortable … And the first change is going to be where your phone is when you’re sleeping. I can no longer allow it to be in your room. I’ve read too much. I know it interferes with your sleep. I know that’s annoying. I know you’re going to protest. I know the first couple of nights you might even feel anxious and have a harder time sleeping … But we’re going to get through all of that, and I know we can, because we’re on the same team.”

Dr. Becky thinks about the exercise as a “boundary hierarchy,” which will allow you to try it more and more, and with harder things—like TikTok—too.

In the end, she says, it’ll teach your children perhaps the most important skill in life: resilience.

“Learning how to struggle is so important. That’s how you find success,” she says. “The better you are at struggling—not in a toxic way, but the better you are at staying in a moment of struggle, the more resilient you can be. And so I think about that as a guiding principle.”

Parenting expert Dr. Becky warns the potential cost of not setting screen-time boundaries for your kids ‘has never been higher’