The only good research I've been able to find is contained in the book "Why We Nap" by Stampi and Broughton. Sounds like we're talking about the same source. Un

The only good research I've been able to find is contained in the book "Why We Nap" by Stampi and Broughton. Sounds like we're talking about the same source. Unfortunately, its no longer in print so therefore very very hard to find.. I'll shoot you an email if I find more.. My co-founder knows more about this stuff than me I'll ask him.