Children’s Responses

Has there been any research in to children’s responses when they find out they have a birth father/ mother whilst believing the father/ mother that they live with is their natural birth parent. If not, has research been carried out surrounding adopted children’s responses to finding out they have birth parents. Could you please advise me on where such information could be accessed if there is any?  
Thank you  

[Kevin Kennedy, Ph.D.]

You'll have to do a literature search to find your answer. Check the ERIC data base and MedLine and you'll some up with some helpful resources.