Is this a conspiracy theory? It sounds a lot like a conspiracy theory to me. Just sayin'.
Conspiracies do happen. However, when you're trying to persuade me of a conspiracy theory, the burden of proof is high. I expect links - lots of them - and good ones. Try to avoid linking to frauds:
http://blogs.nature.com/news/2011/06/did_stephen_jay_gould_f...
FYI, the most accurate IQ tests available at this time were Raven's matrices:
http://en.wikipedia.org/wiki/Ravens_Progressive_Matrices
I think these have lost some reliability because of a training effect from the general popularity of cognitive brainteasers (probably the cause of the Flynn effect). However, it would be interesting to hear someone explain how they were designed by racists to be racist. (Wikipedia tells me they were originally the Coloured Progressive Matrices, which does sound mighty suspicious...)