A word-generation task is a test of retrieval
In verbal-fluency tests, people are often asked to produce as many words as they can under a rule—for example, words beginning with a certain letter or names in a category. The challenge is not simply knowing vocabulary. You have to search memory quickly, avoid repeating yourself, and keep track of the rule while the clock is running.
Taboo words can enter that search readily because they are vivid and often learned in emotionally charged moments. Their strong associations can make them easy to retrieve, much like a memorable phrase or a sharply defined image.
Fluency is more than having a large vocabulary
Generating a word is only part of language use. Speakers also judge whether it fits the situation, how it will sound to others, and whether to hold it back. Swearing appropriately—whether for emphasis, humor, or solidarity—can involve choosing a register, meaning a style of language suited to a particular audience and setting.
That helps explain why taboo-word production can accompany stronger performance on some word-generation tasks: the result may reflect fast access to words, not a special measure of intelligence or proof that swearing causes verbal skill. The same person may retrieve an expletive instantly and still decide, just as quickly, that this is not the moment to use it.
