What is the 'let them' theory? Breaking down the phrase popularized by Mel Robbins that's all about boundaries.

If you’re on the self-help side of social media, there are two words that you may be hearing a lot lately: “Let them.” Fans of the Mel Robbins-backed phrase say it can help you learn to let go of expectations and set boundaries with loved ones — but what does it mean, and how can you incorporate it into your life? Here’s what to know.

What does ‘let them’ mean? Where did it come from?

The phrase “let them” was popularized by author, podcast host and former lawyer Mel Robbins. It is the cornerstone of her new book The Let Them Theory: A Life-Changing Tool That Millions of People Can't Stop Talking About, described as a “a step-by-step guide on how to stop letting other people's opinions, drama, and judgment impact your life.” The theory, she wrote, will “set you free from the exhausting cycle of trying to manage everything and everyone around you.”

Robbins, who wrote in the book that she first learned of the theory from her daughter, initially shared the concept with her social media followers in May 2023. In an Instagram video that now has nearly 1.5 million likes, she said that she had just heard about the “let them” theory, and decided she loved it. “If your friends are not inviting you out to brunch this weekend, let them,” Robbins said. “If the person that you're really attracted to is not interested in a commitment, let them. If your kids do not want to get up and go to that thing with you this week, let them.”

“So much time and energy is wasted on forcing other people to match our expectations,” Robbins continued. “Let them be themselves, because they are revealing who they are to you. Just let them. And then you get to choose what you do next.”

While Robbins has profited off of and repackaged the phrase for her audience, it’s not the first time it has made rounds on social media. In 2022, writer Cassie Phillips’s “Let Them” poem went viral, and features many of the same points that Robbins shares as a part of her theory. Phillips’s poem is regularly shared as a sound TikTok. “If they want to choose something or someone over you, LET THEM,” Phillips wrote. “If they want to go weeks without talking to you, LET THEM. If they are okay with never seeing you, LET THEM. If they are okay with always putting themselves first, LET THEM. If they are showing you who they are and not what you perceived them to be, LET THEM.”

“Let them” as a general concept is also not new, with many people saying that detaching from expectations of others has helped them become happier and more discerning about who is in their life and in what aspect. In a 2024 interview with Oprah Winfrey, Tyler Perry said that his “life got so much better” when he “let people be who they are” and “stopped expecting them to show up the way that I wanted them to.” He shared, “I made the choice whether I was going to continue to be your friend or be in this moment with you or not.”

And Shay Mitchell, on the podcast "Call Her Daddy," shared similar sentiments about no longer trying to control people in her dating life. “I wasted so many sleepless nights, for what? Did that change how he acted? No,” she said, noting that people are going to do what they’re going to do, “regardless if you’re staying up at night, stalking an Instagram.”

Why people love ‘let them’

No matter where people first heard the words “let them” before, the phrase has made an impact. On TikTok, people wax poetic about how “let them” theory has made a significant impact on their lives and relationships.

“Learning the ‘Let Them’ theory was a game-changer,” one person wrote on TikTok. “Instead of wasting energy on things I can’t control, I found peace in letting go. If someone won’t commit or drifts away, just let them. This mindset shift brought emotional freedom and helped me focus on those who genuinely value me.”

Creator Rachel D’Aguanno applied the concept to dating, telling her followers that it’s better to let their significant other cheat, leave or “text another girl” than “drive yourself insane trying to control the situation.” “I know it’s easier said than done, but invoke the ‘let them’ theory here,” she said. “The moment you’re able to adapt the ‘let them’ theory into your mindset and put your faith into the universe and know that God is always on your side and always working for you, a weight is literally lifted off your shoulders.”

Meanwhile, influencer Holly Brooks credited Robbins’s theory specifically with causing a “pivotal moment” in her healing journey. “I think it comes down to this level of understanding that we cannot actually control anything outside of our own narrative,” she explained in a video. “So actually, by letting these people upset us, by doing things that they're probably going to do anyway, it's just causing us unnecessary distress. Also, by letting people just do what they will do, you are able to see their completely true colors.”

Some have even gone so far as to get the words tattooed on their bodies, something that Robbins shared in an Instagram post is “proof of just how powerful these two words really are … and how much they’ve changed not only my life, but yours too.”

What do experts say about ‘let them’?

Kayla Knopp, a clinical psychologist and co-founder of Enamory, a couples therapy private practice based in San Diego, tells Yahoo Life that the “let them” theory is all about making peace with things that are outside of your control — specifically, other people’s feelings and behaviors.

What Knopp likes about the theory is that it’s “really just clever rebranding of the concept of boundaries.” Boundaries are the guidelines we set with others that help us protect our time, energy and emotional well-being in relationships.

While we may let people in our lives behave how they wish to behave, we can set boundaries around what behaviors we will accept, Knopp says. So, if the person you are dating flakes on commitments, you don’t have to constantly argue with them or insist they change their ways. Instead, you can “let them” do what they want, and decide how much energy you wish to put into the relationship. That might mean breaking up with them to seek out someone who is better at meeting your needs.

Caitlin Slavens, psychologist and co-founder of Couples to Cradles Counselling and MamaPsychologists, tells Yahoo Life that the “let them” theory does not mean being a doormat or accepting disrespect. You must “let them” while also respecting yourself — it’s not “go ahead, treat me like crap,” but instead it's about not feeling responsible for other people's actions if they choose to do just that.

“If someone crosses a boundary or mistreats you, ‘let them’ may mean doing so with the understanding that what they’re doing is a reflection of them — not you — and acting accordingly,” she says.

The “let them” theory can even work for parenting, Slavens says. “If an older child repeatedly disregards your household rules, for example, ‘let them’ does not mean to ignore that behavior. It means giving them the experience of the natural consequences of their behavior — as in losing privileges — without engaging in a power struggle.”

Who is the ‘let them’ theory best for?

While anyone can benefit from this practice, Knopp says the “let them” theory can be particularly useful for people who already feel a lot of responsibility to manage and protect people’s feelings and behaviors, such as people pleasers, perfectionists, people with anxious attachment and people who tend toward codependency.

“If you are someone who struggles to hold a boundary if you fear it might hurt someone else's feelings, or someone who can't stand the thought of someone else getting away with doing something wrong, the ‘let them’ theory is for you,” Knopp says. “It helps us refocus our energy on what's actually within our control — our own feelings, behaviors and choices — rather than spinning our wheels trying to control other people.”

Plus, according to Knopp, you may find your relationships improve when you practice letting people be who they are. “No one likes to feel controlled or micromanaged,” she says. “Letting someone else be who they are and experience the natural consequences of their own decisions is actually a sign of respect, and it can help build stronger relationships that are based on mutual respect, trust and healthy interdependence.”