I wonder by how much this could increase IQ?
We don't know. Cochran's theory is not well backed by evidence at this point. Most of it is quite indirect like the attempts at quantifying paternal age effects. Emil didn't turn up anything when I asked the other day. Some of the studies which come to mind which don't support the idea that mutation load matters much:
Spain and Shakeshaft aren't relevant. Marioni is interesting, but I think 1% is way too high a cutoff.
This thread is for asking any questions that might seem obvious, tangential, silly or what-have-you. Don't be shy, everyone has holes in their knowledge, though the fewer and the smaller we can make them, the better.
Please be respectful of other people's admitting ignorance and don't mock them for it, as they're doing a noble thing.