So my wife and I were asked at the outset of our adoption-as-a-first-resort adventure. It was a reasonable question in this age of narrow self-concern — far more reasonable, or at least more reasonably put, than many of the other questions we fielded.

For example, “Why don’t you have your own children?” a wealthy relative inquired, as if natural family-making were a kind of gated community it was best never to abandon. “You two have such good genes,” she added. “Why waste them?”

A colleague at work confronted me in the mailroom with this memorable gem: “Have you tried in-vitro?” She feared that we hadn’t availed ourselves of the many wondrous technologies that rescue infertile couples. “Wouldn’t that be better than adopting a child with a disability?” she asked, drawing out the word “disability.” “God knows what that kid’s parents were doing when they conceived him.”

“We’re not infertile,” I barked. “We have a relationship with the boy.”

My wife, an autism expert, had offered his mother services, but as the woman found it increasingly difficult to care for her son and then dropped out of the picture altogether, we’d started spending time with him. His first communicative act with language, at age 3 — the sign for “more” — we’d taught him while tickling his belly.

He later made that sign in the emergency room of a hospital where he was brought after being beaten in foster care. Upon seeing us — we’d been called in to try to calm him — he stopped in his tracks, paused (as if to allow some associative chain to complete itself) and demanded obsessively to be tickled. I remember searching on his chest for unbruised patches among the purple, blue and black. He was that frantic in his quest for the familiar and, dare I say, for love.

To this day, I can’t believe how callous people were; the strange anxiety that adopting a child with a disability provoked. And the anxiety just kept coming. “Healthy white infants must be tough to get,” a neighbor commented. No paragons of racial sensitivity, we were nevertheless appalled by the idea that we’d do anything to avoid adopting, say, a black child or a Latino one.

As offensive was the assumption that we must be devout Christians: hyperbolic, designated do-gooders with a joint eye firmly on some final prize. “God’s reserving a special place for you,” we heard on more than one occasion, as if our son deserved pity and we were allowed neither our flaws nor a different understanding of social commitment. The journalist Adam Pertman, in his otherwise excellent book, “Adoption Nation,” reproduces this logic exactly when he speaks of “children so challenging that only the most saintly among us would think [my italics] of tackling their behavioral and physical problems.”

Despite the stigma attached to “special-needs children,” people do adopt these kids. And yet, many more Americans spend gobs of money on fertility treatments or travel to foreign countries to find their perfect little bundles. I’m haunted by something my son wrote after we taught him how to read and type on a computer: “I want you to be proud of me. I dream of that because in foster care I had no one.” How many kids lie in bed at night and think something similar?

The physical and behavioral problems have been significant, at times even crushing. The last eight years have been devoted almost exclusively to my son’s welfare: literacy training, occupational therapy, relationship building, counseling for post-traumatic stress — the list goes on and on. But what strides he has made.

The boy who was still in diapers and said to be retarded when he came to live with us is now a straight-A student at our local middle school. He’s literally rewriting the common scripts of autism and “attachment disorder” (the broad diagnosis for the problems of abandoned and traumatized kids). These are hopeless scripts, unforgiving scripts in which the child can’t give back.

My son does, and others can as well. Recently, in response to my hip replacement, he typed on his computer, “I’m nervous because Dad has not brought me braces [his word for crutches].” I was just home from the hospital — wobbly, a bit depressed, in pain. To my question, “Why do you need crutches?” he responded endearingly, “You know how I like to be just like you.” My son was trying to make me feel better, taking on my impairment, limping with me.