I largely agree with the idea of biological connection. With my own son his link to his sister (who doesn't live with us but we maintain the link) is important to him, and he wants to meet up with his birth parents when it is safe for him to do so. His former foster carer is more important to him though, and she is not biologically related. So it isn't a case of either/or. My adopted grandfather hated his birth parents with a passion, but it undeniably was still a connection (he disliked his adopted parents too, for balance :-)). I too would be interested in learning about his birth parents - it affects the next generation too! It is nice to know your own story and have a sense of place in the world.

From a hard evolutionary perspective it doesn't really make a lot of sense though - perhaps that is reflected in the bit mentioning 'God' and 'unnatural' in the same sentence. After all lots of mothers used to die in childbirth and still do in some places. Babies would need to attach to other adults and other adults would need to attach to them, otherwise the babies would die. This is why babies under 3 months old can easily be comforted by any adult. It is only after 3 months or so that they start to recognise and rely on an adult who is their main caregiver.

I do take issue with calling it maternalism. It stems from a very old-fashioned and conservative mindset that it is only mothers who provide that emotional bond. The 'women are caregivers and men are not' attitude in Western societies has been discredited many times, and just reinforces gender stereotypes. It is noticeable that those countries who's societies still promote it have the least enlightened adoption systems and least equal societal systems in general. Can't imagine them allowing gay male couples to adopt for instance.

Compare to the few societies in the world where fathers traditionally are equal caregivers (not many I agree - the Aka tribe in Africa is best known), or even the main caregivers. They'd raise their eyebrows at the idea that only mothers can do the job or make that connection. We need to redefine masculinity and fatherhood just as much as motherhood.