Both, I would say. I think the point he's making is that we ended up with long lives because we needed to live longer, to improve. Basic social structures -- care of each other, burial, basic control over fire -- would be ongoing needs. Why weren't they 'improved upon' over the generations? Maybe if you only knew what your mother could teach you, if she could only teach you what her mother taught her...maybe even the thought of innovation would be foreign. "This is the what we do" is a different thought than "This is the way we do it" -- leaving open the possibility of other ways... (I'm just playing with the idea here -- any thoughts?)
Plus, if an enormous challenge came along every second generation that had to be overcome, having the knowledge of a previous generation would enable the energy to be put into making a tool or procedure better, instead of just 'reinventing the wheel' each time. So, maybe the women found themselves attracted to the men who had had parents who lived just that little bit longer, who had just that little bit extra knowledge, who'd been able to pass something on from their parents...
Maybe that's why I find intelligence sexier than smoldering dark eyes and a broad chest. (Or as Ernie Cline puts it in his hilarious spoken word rant Nerd Porn Auteur, "Guys who know that the sexiest thing in the world is a woman who is smarter than you are!" Seriously, if you haven't checked this guy's stuff out, go and listen.)
Loricat's Book Nook
Celebrating the Absurd
