Indeed, it would seem that if human genetics aren't also changing at a lightning rate, the alternative explanation for the Flynn Effect would have to be that human beings are learning the particular skills called-for to take IQ tests "at a lightning rate".

Does that mean people are learning more skills in general? I don't think so. In fact, it doesn't seem like people are learning the skills on other standardized tests more quickly. What is it about IQ tests that allows scores to increase like this?