Yup. That's about the last I've heard on this too.
Contempory studies have shown that brain size correlates with IQ. Cro-Magnon Man had a larger brain than present day humans...we're breeding down.(?)
I think you are right about that. I wonder which parts of their brains were bigger than ours. I would think that would be important to knowing how smart they were and in what way. I think the horse statue is really nice and doesn't look primitive but very sophisticated.