I'm more than sure that there is a lot of diversity that goes into the eye of the beholder with this inquiry. In my experience, there are at least two main motivators for attraction on this kind of a level: (1) Pathos (the desire to be enthralled...which can manifest itself as the worship, on some level, of the female form); and (2) Sexual Frustration. In my experience, people are attracted to certain qualities depending on how they heighten what one is after. People can pursue a quality in another person simply because they believe it will heighten the frustration...and sometimes qualities are even artificially added, such as in S&M.
These two motivations will most likely see intelligence from totally different perspectives, and if the motivations spur attraction, they will probably manifest different things in mind of the seeker. A Pathos perspective may see intelligence as another manifestation (perhaps even a fuller manifestation) of the female form...or something attractive in and of itself. One who is frustrated by intelligent people, or who seeks to maximize a sense of frustration against/with an intelligent person, would probably approach an intelligent person from the opposite perspective that the person mentioned earlier would. Some people are aroused by praise; others by insults.
Just my two cents.