There is a particular sentence that does more work than almost any other in family life, and it is shorter than most of the lectures parents reach for. The sentence is some variant of: "we don't do that here." Said calmly, said without disgust, said while still keeping a hand on the child's back or eye contact with them, it draws a perimeter without drawing blood. It names a standard that belongs to the household rather than to the moment. It separates the action from the actor. And crucially, it gives the child a place to stand: there is a "we," and the child is inside it.
Compare what most of us were handed instead. "Stop it." "What is wrong with you?" "I told you a hundred times." "Why would you do that?" These sentences perform a different operation. They locate the problem inside the child rather than inside a shared practice. They invite shame, then often invite escalation, because a child who feels rotten about themselves rarely produces the corrected behavior cleanly; they produce more of the same with added defiance, or they produce compliance hollowed out by fear. "We don't do that here" is doing what the other sentences cannot: it is plan-level language. It is the language of a home that has chosen what kind of home it is.
This is a Law 4 move because it is a design decision, made in advance, deployed in the moment. The work of the sentence was done before the incident. Somewhere upstream, the parent decided that yelling at a sibling was not part of the house, or that food was not thrown, or that pets were not grabbed by the tail. The sentence in the kitchen is the deployment of a plan, not the invention of one. Most parenting friction comes from trying to invent the plan during the incident, when the prefrontal cortex of both adult and child is offline and the only available material is fight, flight, or freeze. By contrast, a household with a small clear set of "we don'ts" runs on something closer to muscle memory.
The sentence also functions as an identity statement, which is why it has more durability than rules announced as rules. "No hitting" is a regulation; the child can break it and remain themselves. "We don't hit in this family" is a description; to break it is to step briefly outside of who we are, and the natural pull is to step back inside. Carol Dweck's work on identity language and Adam Grant's writing on values-based phrasing both point in the same direction: people, including small ones, do not maintain rules they have to memorize, but they do maintain identities they have been given. When the parent says "we," the child borrows that "we" until it becomes their own. This is the quiet engine of unspoken culture, which is Law 1's territory: the child is being initiated into a unity, not enrolled in a regulation scheme.
What the sentence is not, when it is working well, is a euphemism for "stop doing the thing that irritates me." Parents drift into using "we don't do that here" as a softer "knock it off," and the child detects the bait-and-switch immediately. The sentence loses its force the moment it becomes a stylish way to dominate. It also fails when the "we" is a lie, when the adult clearly does do that here, just louder. A father who yells "we don't yell in this house" has burned the instrument. The sentence is a covenant with the speaker first; only then is it usable on the child.
Practically, the sentence wants three things from the parent. First, the household has to have actually decided what its "we don'ts" are, and the list should be short, maybe four to six things, not thirty. Second, the parent has to be willing to apply the sentence to themselves out loud when they slip: "I yelled. We don't yell in this house. I'm sorry." This is the repair move, and it is the thing that keeps the covenant alive across the inevitable failures. Third, the sentence has to be followed by a redirection, not a void. "We don't do that here. Here's what you can do instead." Otherwise the child is left holding a prohibition without a path, which is the condition under which prohibitions get broken.
Done well, the sentence is one of the most economical instruments in parenting: a small piece of language carrying a large piece of structure, applied without theatre, leaving the relationship intact and the standard clearer than before.