Overall, I found the book to be an enjoyable read.
Author Satoshi Kanazawa begins by positing that a sort of inflationary trend has taken hold among academic psychologists, who, uncomfortable with some of the contrasts and divisions that psychometric testing has revealed among different groups of individuals, have attempted to broaden the definition of "intelligence" to be far more inclusive. This mindset, he argues, arises from a tendency in our culture to view intelligence as the ultimate measure of human worth. He then goes on to make a case for why intelligence should not be viewed as the ultimate measure of human worth.
Kanazawa makes a well-supported and pretty convincing case that "intelligence" is actually a measure of facility and affinity for evolutionarily novel behaviors and skills. He also posits that the aforementioned affinity for evolutionarily novel behaviors is, paradoxically, often maladaptive both in evolutionary terms and in terms of helping those individuals secure an overall higher quality of life - due mostly to their oddball tendencies that tends to put them at odds with the mainstream majority. This is Kanazawa's central thesis and is what gives rise to the book title, The Intelligence Paradox and its subtitle, "Why the Intelligent Choice Isn't Always the Smart One".
The reason I have not rated this book "excellent" is that his attempts to draw attention to our culture's erroneous conflation of intelligence with human worth seemed somewhat disingenuous to me - it seems to smack somewhat of academic sanctimony. I'm not entirely convinced that Kanazawa really believes that intelligence should not be seen as a measure of human worth. But this is only my impression, and his arguments, while perhaps controversial to some, are still well presented and worth serious consideration.