That is the new book by David Epstein, the author of the excellent The Sports Gene. I sometimes say that generalists are the most specialized people of them all, so specialized they can’t in fact do anything. Except make observations of that nature. Excerpt:
In an impressively insightful image, Tetlock described the very best forecasters as foxes with dragonfly eyes. Dragonfly eyes are composed of tens of thousands of lenses, each with a different perspective, which are then synthesized in the dragonfly’s brain.
I am not sure Epstein figures out what a generalist really is (and how does a generalist differ from a polymath, by the way?), but this book is the best place to start for thinking about the relevant issues.