I just read a short, but interesting article on a science blog by Rick Hanson, Ph.D., The Evolution of Love
Kinda sounds to me like he's been reading Marnia's articles, though he doesn't mention Karezza, but he's very down with Oxytocin bonding.
Here's a quote from it:
Humans are the most sociable species on earth – for better and for worse.
On the one hand, we have the greatest capacities for empathy, communication, friendship, romance, complex social structures, and altruism. On the other, we have the greatest capacities for shaming, emotional cruelty, sadism, envy, jealousy, discrimination and other forms of dehumanization, and wholesale slaughter of our fellow humans.
It's not in depth, but he does mention future articles.
Be sure to check out the author's links to his book, Buddhas Brain, and the Wisebrain site!
We need more Scientists talking about this in clear, understandable terms, to balance out the 'facts' of historical anthropology that's been in the best seller, "Sex at Dawn".