The author of the article has several books out with the same premise, so it isn't a big leap that he'd make the same assumptions here. But I think a couple of assumptions require the use of a pretty broad brush - that all kids find the described test boring, thus leading to his assumption that it was lack of motivation that caused the results, and that a lack of motivation at one stage of life in one specific circumstance is a predictor of success or failure.
Oh, and the assumption that a kid who scores a 79 or 97 is going to end up average. That's a bit black and white as well. IQ tests have their place and do provide vital insight, but they are not perfect, nor do they provide accurate results in all cases. Many of us here know that first-hand.
