The more that I research adoption I have come to realize that so much focus is on the adoptees and their mental state that we tend to forget that the biological siblings and the adopted siblings may need counseling as well. Siblings suffer on both ends. I know that my adopted brothers had a hard time with me instantly coming into the family. They do not tell me that directly but by the stories they tell I can feel the resentment and jealously that they endured as little guys. I feel like my parents and grandparents put too much emphasis on me. They made my brothers feel like I was something that they could not touch like they put me on a pedestal. If you do this with children that you adopt it could easily make the siblings resent them from the very beginning. My parents I feel tried a little too hard to make me their own and prove themselves as my parents. They adopted me and took me in as their own that in itself makes their love special. They did not have to prove anything. I strongly recommend that adopted parents still take individual time with their biological children to keep this resentment from coming. Talk to them often to let them know how special each of your children are to you.
As for the biological siblings they sometimes have their own crosses to bear. They suffer a loss from either being separated from the siblings that went to foster care or was adopted. If they find out later in life they may have many feelings of hate, betrayal and resentment. In my adoption I had a older sister when I was put up for adoption as well as my birth mom had a younger boy after me. This caused my older sister to question why my mom gave her sister up and kept her. I really do not know how my younger brother felt but life was much harder at home for my sister. There were deep dark secrets in the family that caused my sister great pain. These secrets were kept from my brother. In so many families I have seen where there is a child (golden child) that gets great treatment and the other children get the abuse or the worst treatment. Well this happened with my biological siblings. Fifty some years later my sister has finally trusted enough to reach out and get therapy. There is NO shame in asking for help. What you do to children when they are young can scar them for life. My whole point is that with adoption we need to help every family member that suffers loss in the adoption world. I have finally decided to let go of my resentment for being the only one of three to be given away by my birth mother. I blamed myself for not being there for my sister. I felt rejected by my birth mother but I have come to realize that is not my cross to bear. I can help my sister now and I escaped some really bad things by being put up for adoption! I want to look at the glass as half-full.