On the other hand, while Walker may be right about everything he says (anecdotally I'm extremely aware of how important sleep is day-to-day), I found his book to be very poor evidence of what he's trying to persuade us of. His writing is that of one who has bought unquestioningly into a cult. The evo-psych digressions about "wise Mother Nature" are nothing short of ridiculous; the one that sticks in my memory is that he seriously considers the possibility that Nature gave teenagers an offset sleep cycle from adults so that they could start exploring the world on their own for a few hours each night. (One much simpler possible explanation is that it gave the tribe someone who was naturally on guard duty for more of the night, but of course this is testable by looking at non-tribal animals and I haven't tested it.)
As alecco says in this thread, it is indeed a hardcore scientist who studied sleep for twenty years trying to communicate to a wider audience. I'll cut him a lot of slack.
Also, not sure if you've seen Walker speak (do check out on YouTube), he's one of the most brilliant public speakers. Very few scientists can manage to hold your concentration like Prof. Walker does.
