It's been a few years since I read it, so I didn't recall that. Is it stated or just implied?

Still, I remain unconvinced of the author's depictions of a lack of consciousness. The problem is the "philosophical zombie". It looks and acts, to all accounts, like a normal human, but has no internal experience. Since I can't even prove anybody else has experience (despite acting a lot like me), what's the basis for different behavior just because an organism lacks consciousness?

I found it intriguing but unlikely, based on evolutionary fitness.

Your selection arguments make sense to me. We are conscious, so consciousness must increase fitness. Maybe impulse control is a key aspect of it. And thinking of Hofstadter, maybe it's just the top of the self-referential stack.

Impulse control could be part of it, but it's not clear that that requires consciousness, either :)

We know that perceptual awareness has some connection to biology (sleep, seizures, drugs, etc), so to the extent that consciousness requires energy, it has to justify its caloric expenditure.

Lrf. Ubjrire, ng gur fgneg bs Rpubcenkvn, V trg gung inzcverf fvzhygnarbhfyl eha frireny ernyvgvrf. Ohg vg'f abg lrg pyrne gb zr jurgure gurl'er nygreangr fpranevbf, whfg sbe nzhfrzrag, be jungrire.