Great post, ColinsMum.

I think aculady's point about crystallized intelligence is a good one, too. The effects of testing assumptions, made when crafting a test for a wide range, must be very different for young kids. For me, it goes back to my distrust of relying on any sort of early milestones as a hard predictor of intelligence levels or future performance, although I think a child who hits milestones early under her own steam will be more likely to be on her way to genius.