@Neizvestnaya I would think the fact that the parents who raised them kept this truth from them their whole life affects those feelings? I would also guess sometimes maybe if the adopted adult had a difficult childhood and did not get along well with their adoptive parents it would make someone even more resentful, or feel the need to know their bioloigcal parents. I don’t know, tis is just hypothesizing on my part not an firmly held opinion of mine or anything.
In my case there is a running joke in my family that my sister tries to throw at me all of the time because I was born from artifical insemination and she looks so much like my dad, and me very little, so she tells me I am the doctors baby. I actually do have some body features just like him, and she will just say tons of people have those feature. One day she asked me what would I really do if it were true my dad is not my bio dad, and I am pretty sure I would do nothing. But, that is not my parents lying to me my whole life.
I think if I was adopted as a child, and knew my whole life I was adopted, I would wonder also. I would want to know my bio parents. Can’t be sure though, hard to know what my 10 year old mind would be thinking, and then later that mind nto adulthood. If I found out I was adopted now, I think I would be curious to the circumstance maybe? Not sure. I really am not sure.