What scares some adoptive parents about telling their child s/he is adopted?

Mei-Ling Hopgood's Lucky Girl asks this question. Adopted from Taiwan and raised in the midwest, Hopgood explains,

I sometimes resented people's assumption that adoptees must automatically, deep down, feel part empty or abandoned, that we must suffer some hole in us that will never be filled because our birth parents could not or did not raise us. I know people think this. I know because psychologists and adoption experts write essays and books about it. I know because of the questions people ask ("Did you always know you were adopted?" "How did you feel about that?") as if being adopted might mean you are somehow incomplete.

I also understand that adopted parents worry a lot about this. I've talked to parents who pine and mourn for their child's birth mother and father and fret over whether their baby will despair at not being able to know or find their birth family. I know parents who fear telling their child that he or she is adopted, which is ridiculous, in my view. The longer you conceal this so-called secret, the more likely it will become toxic.

I think there are people who do feel abandoned and betrayed, but I hear Hopgood's point; an individual's reaction to his or her adoption will depend on that individual's personality and circumstances. I suppose then, the answer to my title question has to be similarly nuanced. Individuals and individual couples will have different approaches to and reasons for their explanations about their kid's adoption.

A few prominent reasons come to mind for parents NOT telling their kids about their adoptions. Jealousy/fear of emotional detachment. Just as there is the possibility for children to feel pushed away by biological parents, adoptive parents could feel pushed away when their children seek out those biological families. Desire to protect their children from painful identity struggle. Genuine belief that adoption does put a child at a disadvantage in some way. Shame at not having been able to conceive a child themselves.

My Nanny and her husband chose to tell the girls from early on, as did Hopgood's parents. One ugly side of that coin, however, was that when my mom and aunt misbehaved, their father would tell people they were adopted, while good behavior was rewarded with "That's my girl."

It seems to me that the honest conversation bit is still families'--of any kind--best bet.