I do not think that someone deserves special treatment just because they happen to be the son, daughter, mother, father, brother, or sister of someone else. What difference does it make if people share the same ancestors or whether they are a descendant of someone. I think that family is more about choice than it is about genetics. An adopted child should not feel like they are less than a sibling which was born into a family. Why should parents act like a child being conceived from their sperm or egg is somehow better than the child of someone else, far across the world, that they will never meet?
Take for example a situation where a baby boy is left in a basket at the front door of the Smith family. They open the door and discover a baby of unknown origin. They decide to just raise this baby in their family and call him John. Suppose one day that John asks his parents where he came from. They can tell him that they found him in a basket years ago and that they have no clue where he was before that. The amazing thing is that it will be years before he will even ask that.
The origin of where John came from is irrelevant. It is unlikely that other people will even know that he wasn’t born into the family and it is none of their business anyhow.
A child who is adopted when they are much older needs to understand that, if anything, they should feel loved BECAUSE they were CHOSEN to be part of the family.
Those who have animals as pets that you consider part of the family as much as any human children can understand my point exactly. They can understand what I truly meant about physical appearance being irrelevant.