Many disbelievers in Shenk's theory are disputing it and arguing with him online. On the book's page at Amazon, you'll find an amazing array of customer reviews and a video that you can link to directly. A Google Search on the author's name will lead you to many sites where these issues are debated. Some people accuse Shenk of misinterpreting the studies he used and others point to faulty logic. The blizzard of data cited in the book tends to obscure the reality that he is theorizing a posteriori or post facto (after the facts), a practice frowned upon in research.
Despite all the high level scientific mumbo jumbo cited in the book, it is easy to read. Shenk writes in a very approachable everyday conversational style, which may have been just what the publisher wanted. Apparently with no advanced degree to boost credibility and no authoritative co-author, Shenk has pulled off a good one. The end notes are a fascinating read, and the bibliography provides a long term reading list.
Too bad he came to an inaccurate conclusion. All my 66 years of experience with giftedness, achievement (or lack or it), and people at the far-out end of the IQ spectrum provide a strong gut feeling of wrongness about The Genius in All of Us.
Perhaps journalists should stick to reporting the news from areas like epigenetics and cognitive science and the psychology of high achievement instead of creating a mashup that offers false hope and clashes with the realities of human life.