What if some crazy wizard created an artifact that empowered rodents that touched it with one random supernatural power? Preferly right out of the pages of your favorite four-color. (But only one power!) This item does not convey any sort of intelligence boost.
Somewhere along the line, someone very powerful lost their marbles. Literally. Possessing a marble allows incredible clarity of thought about a particular related subject.
A people who believe it is incredibly impolite to speak to anybody they meet for the first time. They believe their actions should speak for them until they are comfortable in each others presence and can then trust each other. Only then would converstation be appropriate.