Why do we love our pets so much? hmmm, well, maybe 'cause they're not as crazy and obnoxious as other humans! lol... it seems so obvious, I don't know how 'Nature' can get a whole show out of it... ;D
Seriously, tho, thatnks for the heads-up -- looks interesting!
If you view them as unconditional love relationships they are on par with child rearing,
as for the most part an animal 'owner' is much more a 'care giver'.