If i recall correctly, men who are bonded (via sex of course given the huge oxytocin releases) to their childrens mother and who saw the mother throughout pregn

If i recall correctly, men who are bonded (via sex of course given the huge oxytocin releases) to their childrens mother and who saw the mother throughout pregnancy and were sure there was no cheating have a higher affinity to that child and this can be measured hormonally. Its not 100 percent but probably good enough for natural selection. Also marriage and pair bonding is rather common among our closely related primate brethren Edit: also the testosterone stuff is mostly a myth in the sense that, while testosterone of new fathers drops, it also recovers some months after the baby is born and older. So you get some months of baby snuggles and then you're back with your old libido. Also, men with kids are way more attractive to women (including their wives) anyway.