A large part of the book is composed of introductory lessons on the history, science and treatment choices of each condition. This context is necessary, but occasionally cumbersome. Solomon is not a physician or social scientist. Experts in each field will no doubt have bones to pick with his methodology — the size of the cross-cultural cohort, for example, or the heavy skewing of his samples toward people of means. The book’s structure is a bit awkward because, despite 199 pages of bibliography and footnotes (merely “a compressed form,” he reminds us, and to be found “at greater length online”), the overall approach is more journalistic than scholarly. Given the amount of material he has synthesized, Solomon might have offered more of an overarching theory about the qualities of the successful parents. Rather too insistently he just emphasizes, and praises, their positive outlooks, their ability to play uncomplainingly the hand they’re dealt.

That said, Far From the Tree doesn’t purport to be an original work of theoretical research on family dynamics. It’s more of a hybrid series of thematically linked oral histories, the majority of which are deeply moving about the strength of parents who display heroic energy and creativity. Here is how Emily and Charles work to stimulate their profoundly retarded newborn, and the sort of detail Solomon is consistently able to draw from his subjects:

“Emily sewed a quilt that had a different fabric every few inches — terry cloth, velvet, AstroTurf — so that every time Jason moved he would experience a new sensation. When he was six months old, they took a giant roasting pan and filled it with Jell-O, forty packages’ worth, and lowered him into it so he could writhe around and experience the strange texture, and eat some of it, too. They used brushes on the soles of his feet to make his toes curl up.”

The pair who most exemplify the altruistic, self-aware love that Solomon celebrates are Tom and Sue Klebold. Their son was Dylan, one of the two teenagers who rampaged at Columbine High School on April 20, 1999. The number of dead from that horrific event is generally listed at 13, but the two perpetrators also died. Tom and Sue were utterly blindsided by the event and had to deal with not only their own shock and grief but being ostracized from their Colorado community. “I can never decide whether it’s worse to think your child was hardwired to be like this and that you couldn’t have done anything, or to think he was a good person and something set this off in him,” Sue says. “What I’ve learned from being an outcast since the tragedy has given me insight into what it must have felt like for my son to be marginalized.”

With this and many of the other profiles he has so assiduously collected, Solomon allows his readers to witness the “extraordinary clarity” of such love.

Lisa Zeidner reviewed this book for The Washington Post.