Integrity is not honesty. They get used interchangeably and they're different values doing different jobs. Honesty is about accuracy — whether what you say matches what's true. Integrity is about alignment — whether what you do matches what you said. Someone can be scrupulously honest and have poor integrity: never lies, never quite delivers. The reverse exists too, and is worse.
You don't get to grade yourself on it. Integrity is measured by the people watching, not by your own sense of your intentions. The research treats it as a perceived alignment between words and deeds, which means the only assessment that counts is the one being made by people who weren't in your head when you made the promise. They can't see that you meant it. They can only see what happened.
It erodes gradually, which is why it's hard to catch. People notice a sudden ethical jump and largely miss the same distance travelled in small steps. Nobody decides to become someone whose word means less. They make a reasonable exception, then another, each one defensible against the one before it — and the drift never registers, because there was never a moment where the change was big enough to see.
And it can be held too tightly. A commitment that has become harmful is still a commitment, and refusing to revisit it isn't integrity — it's using consistency as a place to hide. Integrity means your word is good. It doesn't mean you were right.
That's what integrity is — not a claim you make about yourself, but the size of the gap between what you said and what you did.