Indeed, this is what I use. It feels much more natural to me in the following case, where obviously our statement is not a question:
Dr Johnson kicked a large rock, and said, as his foot rebounded, “Do I refute it thus?”.
And “obviously” the full stop should go outside, because of:
Dr Johnson kicked a large rock, and said, as his foot rebounded, “Do I refute it thus?”, howling with pain.
And there’s nothing special about a question mark, so this rule should be identical if a full stop is substituted.
I stopped taking the book seriously when I reached Walker’s suggestion that teenagers might have a sleep cycle offset from adults because “wise Mother Nature” was giving them the chance to develop independence from the tribe, in a group of their peers, and that this was an important stage in societal development of a human.
If one *must* find an evo-psych explanation for this phenomenon, surely “we need people guarding the camp at more hours of the day” is simpler and less ridiculously tenuous. (Though this still has precisely the same “I could have explained anything with this” flavour that most popular evo-psych does.)