Culture is what you tolerate, not what you say
Culture posters lie. Behavior on a Tuesday afternoon tells the truth.
Culture is the worst behavior you'll tolerate
Whatever the lowest performer is doing on their worst day is your actual culture, no matter what the values poster says.
It's set by what you do, not what you say
If you say 'we put the customer first' and then trash-talk a customer in the break room, the team learned the lesson you actually taught.
Small ratchets matter
You don't fix culture in a meeting. You fix it by raising the bar one specific behavior at a time over months.
Take your version of this question further
This is one operator-tested angle on the question. Your shop, your size, your trade, and your team change the answer. Ask your specific version inside Ask a Shop Owner to get a response grounded in how owners like you actually handled it.