“Considering that neither paper addresses the USA at all, it would be absolutely remarkable if either of them had.”
Sorry Vox but the first paper does discuss the USA – it is the second paper that doesn’t. Lynn & Dutton discuss the US saying “However, there remains the problem that phenotypic intelligence has continued to increase in recent years in the United States (Flynn, 2012, Table A11i, p.238), despite evidence for dysgenic fertility reviewed in Lynn (2011) and confirmed by Meisenberg (2014). This inconsistency remains one of a number of un- resolved problems.” and cite the gains in WISC-III and WISC-IV scores in table 1 (IQ gains in USA and Britain).
So, where the researchers find a decline it isn’t attributable to immigration because of the relatively small impact immigration could have and where immigration could have a larger impact the ‘declines’ are more ambiguous (or possibly rises).
Meanwhile, the brilliant counter-argument from Vox is him posting an estimate of his vocabulary size from a free internet quiz. 🙂