It doesn't matter to me that much. I've had a range of academic/measurable intelligence in my partners. I've never dated anyone I consider dumb, though; the people I'm attracted to are typically quick-witted, creative and very into their fields of interest.
When it comes down to it, I think I like my partners to know more than me about something, be it something academic like psychology, mathematics, or philosophy, or something a little more everyday like music, art, fashion, or computers. I like being able to learn and experience new things. I don't need to bore people with my dry law school shit. I'd rather they show me their knowledge, even if it's just showing me how they cook or taking me to dance classes or whatever.
I like feeling like I'm on the same level in a relationship. I'm just not a dominant person. And I think I would be really frustrated if I was dating someone I couldn't have an intelligent conversation or debate with...