New Zealand's adoption law is outdated and needs to be changed, an adoption researcher says.
Auckland University of Technology lecturer Rhoda Scherman said most adoptions today were encouraged to be open to allow for the sharing of details about biological parents, she said.
"It might be merely the sharing of identifying information, it might be cards or letters once a year, it might be that the birth family and the adoptive family live in the same town and have regular visits," she said.
Dr Scherman moved to New Zealand 20 years ago and said most adoptions here had a high degree of openness, which she believed was influenced by the value Maori placed on their connection with whanau.
"When I look around and say what's different about New Zealand? I see an indigenous culture with this same ethos...I can't help but believe it is an implicit role that is played by our indigenous culture," she said.
In 1985, a new law was passed enabling mature adoptees to access details about their biological parents.
University of Canterbury lecturer Annabel Ahuriri-Driscoll was adopted and said it was important to know where you came from.
"Not growing up with your birth family does put you at a disadvantage," she said.
"Certainly with the Maori world, it is about not having the knowledge, or being brought up in an environment where that there is no connection to that. And I think people have at a really deep level a lack of confidence about standing up and saying I am Maori."
However, Dr Scherman said the 1955 Adoption Act still reflected the old closed adoption system.
It included sealing records and severing ties of the adopted child to the birth family.
"We have this shockingly antiquated adoption legislation from 1955 that doesn't encourage best practice and certainly doesn't reflect current practice," she said.
"It is the spirit of it that I wish to see changed, and there are many people who wish to see it changed."
Ms Ahuriri-Driscoll agreed and said the Act and closed stranger adoptions did not fit well with Maori values or perspectives.
"There is this very strong feeling that adoption is abhorrent...It disrupts whakapapa."
Ms Ahuriri-Driscoll has been interviewing other Maori adoptees and said there was not enough support for them to talk about their struggles or to learn their whakapapa.