The science shows that children are best served when raised by their biological mothers and fathers. This is a point that I have made repeatedly in debates over same-sex marriage. But recently I was pulled up by Anne, the mother of an adopted child. She wondered if I regarded heterosexual parents who adopt as being abusive.

The short answer is No; there is a moral difference between adoption by same-sex couples and heterosexual couples. Let me explain why in my open letter to Anne.

Anne, thank you for raising this issue.

I don’t want to complicate the issue unnecessarily, but we need to distinguish four terms: “primary-intended deprivation,” “primary-unintended deprivation,” “secondary-intended deprivation,” and “secondary-unintended deprivation.”

Let’s start with “primary-intended deprivation”. This occurs when a child could be raised by the biological mother and father and this deliberately does not happen. This happens with IVF using donor eggs and sperm and a surrogate mother. Some governments think that this is a good, or at least permissible, situation.

Our second term is “primary-unintended deprivation.” The most common instance of this is divorce. Divorce deprives a child of a mother or father, but this is not necessarily deliberate. One parent might even oppose separation. The death of one or both parents also causes unintended deprivation. No government welcomes the impact of divorce or death on children.

Now to our third and fourth terms, which are relevant to your situation. “Secondary deprivations” occur after the child already has experienced a primary deprivation.

A “secondary-unintended deprivation” occurs after a child already has been separated from a biological mother or father. Adoption is an example of this. No wholesome reunion with the biological mother and father is possible. What is needed is to pick up the pieces in the child’s life — which you have done so generously. Yes, the child has been deprived of his or her biological mother and father, but you had no part in it.

With “secondary-intended deprivation”, too, a deprivation has already occurred on the primary level, ie relating to the biological parents. But the adopting parents reinforce this pattern of deprivation. In the case of same-sex adoption, a child is deprived of two things: gender complementarity of those who raise the child and – so the research suggests — a stable adult union.

With our terms defined, let us examine the specific differences among five different family structures: (1) same-sex couples creating children with IVF and surrogacy; (2) same-sex couples raising a biological child after a divorce from a heterosexual partner; (3) adoptive heterosexual couples; (4) adoptive single mothers; and (5) same-sex couples adopting.

(1) When same-sex couples create children with reproductive technologies, they deliberately deprive them of a biological mother or a father or both. When governments allow this, they are permitting the deliberate deprivation of a child of  a major theme of development. I would call this state-sanctioned child abuse.

(2) Same-sex couples raising a biological child after divorce from a heterosexual partner. This “secondary-intended deprivation” is a common scenario among lesbian couples. The child has been deprived of a father figure (or possibly a mother figure). This also deliberately deprives a child of a major theme of development. If the couple breaks up, as often happens, the child is also deprived of his or her need for a stable environment.

(3) Adoptive heterosexual couples. This is an example of “secondary-unintended deprivation.” The primary deprivation would not be your fault. You are satisfying the child’s need for gender complementarity in its parents. Hopefully, for the child’s sake, your relationship will be stable. Most are.

(4) Adoptive single mothers. If the mother did not intend to be partnerless, this is a case of “secondary-unintended deprivation”. In any case a single woman might marry and give her child an adoptive father as a role-model of manhood. Of course, this scenario is far from ideal, but it is not abusive because it is not a situation which deliberately deprives a child of a major theme of development.

(5) Same-sex couples adopting. This is a case of “secondary-intentional deprivation.” It deliberately deprives the child after he or she already has been deprived on the primary level. This is not a healthy situation. The government knows that a child up for adoption has already lost its biological parents. Nonetheless it permits even more deprivation – of gender complementarity and possibly of marital stability.

Once again, I conclude that a government which permits a child to be deprived of a major theme of development is engaging in state-sanctioned child abuse.

Anne, what you are doing is heroic. Are you now willing to take another courageous stand: to say Yes to traditional view of marriage as the union of a man and a woman? For the sake of the next generation, I hope your answer is, “Yes.”

Richard Fitzgibbons is the director of Comprehensive Counseling Services in West Conshohocken, PA. He has practiced psychiatry for 34 years with a specialty in the treatment of excessive anger. He co-authored Helping Clients Forgive: An Empirical Guide for Resolving Anger and Restoring Hope, 2000, for American Psychological Association Books.