In which constellation does Mercury fall? People are the smartest. What about Mercury Aries? What's the ranking?

Generally speaking, Gemini is smarter when Mercury falls in Aquarius, because it will be influenced by Uranus in Aquarius. Gemini is Mercury's guardian constellation. But this is only one aspect. Smart or not, you can't just look at the constellation Mercury, the life span of the sun, the phase between the moon and Mercury, and so on. The most direct influence of Mercury constellation is people's thinking mode.

Mercury Aries is not an ideal constellation, but it can't be said that it is not smart. It can only be said that the way of thinking and language habits have the characteristics of Aries.