Three-Toed Sloth has a thoughtful examination of heritability in IQ, complete with disclaimer:

Attention conservation notice: It's long, and it's about something which makes eyes glaze over even as tempers flare up, and it's not funny at all. Worse yet, more is on the way. You could always read it later, but time spent now is gone forever.

The conclusion? IQ may depend much less on your genetic heritage than previously assumed. I find some of his arguments quite convincing.