I don't think it's really the case that "much of this discussion assumes" certain behaviors as being indicative of consciousness. Rather, it has been the case until recently that behaviorists pointed to various behaviors as being unique to humans, and jumped to the conclusion that this indicates that humans are conscious and other animals aren't. What has been happening recently is that one by one these behaviors have been show as not being truly unique to humans. It is becoming more and more undeniable that even when humans are fairly unique in the quantity of some of these characteristics, none of them are completely absent in all other animals, and many can be found to some degree even in very simple animals.