You're handwaving away the nutrition hypothesis for the Flynn Effect, and I think losing sight of the timeline for the comparison. It's going to be very difficult to make any case like this if we're looking back to 1900, which is what we're doing when we talk about the nutrition/intelligence shifts we see in stats.

▲ delichon 3 hours ago | parent [-]

We seem to be having different conversations. I'm responding to

  if we know for sure the genes are the same and nature is off the table, how much variance remains?

... and saying that nature isn't off the table at all. Are you saying that it is?

	▲	tptacek 3 hours ago \| parent [-]
		For intelligence? Where "nature" refers to "innateness" of the trait? I think it mostly is off the table, yes. I'm not saying that the only or even the most important environmental trait is nutrition. (I think it can't possibly be entirely off the table, since we have mechanistic understanding of some gene-mediated cognitive disabilities).