Based on Andrew Solomon’s nonfiction book, this documentary looks at several families with children who are different in some way. Most of the children have a disability (autism, Down syndrome, dwarfism), but one is a young man who’s serving a life sentence for murdering an eight-year-old boy. Director Rachel Dretzin, shifting between profiles of parents and children, displays sympathy toward both sets of subjects, but her compassionate perspective is most illuminating when she considers the older generation—few movies convey so clearly the unique stress of raising children with severe disabilities. Dretzin undercuts the emotional power of her interviews by putting in way too much sentimental music, and one might wish she had considered her subjects in greater depth. But this is still a serious and unpatronizing take on a difficult topic.