I was really looking forward to this one, having read all of Po Bronson's previous stuff (was mostly highly impressed), and being highly interested in the topic. My expectations might have been coloured by that in the sense that I was expecting a more comprehensive treatise on all interesting developments in child psychology over the last 20 years.
Overall a 4/5, for the simple fact that the result that came out from the research that went in, was a bit too sparse in my opinion. While I have no trouble agreeing to all the findings and very much like the process of showing how iterative efforts are necessary at uncovering working principles, as opposed to intuitively appealing concepts, which tend not to be borne out of practice, I have expected a more thorough analysis of the issues.
Another negative for me was a somewhat lacking introduction, where the authors would explain in more detail, why the specific aspects discussed were chosen, whether those are all the areas, where a change of perspective took place, and if not, why the authors considered those most important.
On the plus side, the conclusions drawn do not ever seem flimsy and complete references are included. The authors also successfully avoid the current trend towards endlessly repeating the same basic concept with different examples, so the 239 pages of content have been thoroughly combed through with Occam's razor. The style, however, seems to strongly mirror what they would have used in the newspaper articles, which predated this book (and were based on the same research), which makes the book very readable but I personally found less than optimal in the book format, where I felt the authors would provide much more depth to the reasoning and the conclusions.
To summarise, if one reads the book as a parent in search of tips how to make their child nurturing more effective, the book delivers to the full. If one is interested in a more abstract fashion in what developments took place in child / developmental psychology in the last 20 years but does not have the time to follow the relevant literature on a regular basis, the book is still OK but not a 5 star.