An important aspect of adoption is access to information about natural parentage.
I don't know if I'm the right person to comment on this, being adopted myself, I'm emotionally involved in the subject and it may colour my comments too much. My own access to information was unproblematic. I had a copy of the original adoption paper stating my mothers' name. This was done prior to the 1955 Adoption Act.
And you will see in any official discussion on the subject of adoption, that emphasis is on the acting adults in the situation, what protects them and their information. From what? Emotional harm? No. I think its more the system, designed by emotionless officialdom, that tries to send the adults on their journey in life without fear of repercussion. After all, they are the taxpayers. Babies don't pay tax and can't speak for themselves.
In the discussion paper submitted by the Privacy Commissioner to the Law Commission labelled 'Options for Reform' 2000, the Privacy Commissioner argues for a more open information system and discusses the modern problem of artifical reproduction, the other aspect of natural parentage which will become of interest in the future for those growing up at present.
People are largely a product of their ancestors. When we look back at these ancestors, we see the traits we notice in ourselves and its comforting to realise that our lifetimes are coloured by theirs and that we are part of a much larger family. To be denied access to that heritage is quite unsound. Our foster parents belong to a different branch of humanity and although its interesting, its not personal except for the love we have for them.
In the families I have researched in depth, I've noticed that these traits do repeat. Take a look at my foster mother's family and my natural father's family and you will perhaps notice that these families have different behavioural aspects. You can't deny blood.
My husbands family is different again. I visited some people with the same surname in Napier once, not knowing where they fitted in. The wife said her husband (70yrs) was in bed (8pm) because although he was retired, he ran a pig farm and got up early to feed out. Although we could not connect our families, I thought they must be related somewhere because my husbands ancestors did exactly what this chap was doing, working till he dropped!