Why does John Searle describe greetings and thanks as having a null direction of fit?

John Searle describes speech acts such as greetings and thanks as having a "null" direction of fit because they do not function to match words to the world, nor do they attempt to make the world match words.1

In Searle’s speech act theory, the "direction of fit" characterizes how an utterance relates to reality. For instance, statements have a "word-to-world" fit because they aim to describe how the world is, while promises have a "world-to-word" fit because the speaker commits to changing the world to align with their words. Because greetings and thanks—which Searle classifies as expressives—do not involve these specific representational or commissive functions, they fall outside of those two categories, resulting in a null direction of fit.1