There are two very good reasons this year — or any year — for Americans to expand their understanding of so-called hillbillies, the mostly white people of Scots-Irish stock who are found in the mountainous east-central part of the United States. The first reason is that these people are showing advanced symptoms of the problem that is afflicting middle-class Americans at this time — economic inequality. The second is that these people may well vote in numbers this time.

With "Hillbilly Elegy: A Memoir of a Family and Culture in Crisis," J.D. Vance has written a book that goes some way to helping the rest of us understand what makes these people tick, and the lives that they lead that cause them to behave the way they do. His family is from Jackson, Ky., where the men worked in the coal mines until there weren't any, then moved to Middletown, Ohio, to jobs at Armco Kawasaki Steel, until that went away.

Vance got out, serving as a Marine in Iraq and subsequently attending Ohio State University and then Yale Law School before ending up at a Silicon Valley investment firm near San Francisco. His was a classic "I got out of there."

Except that he didn't. The loyalty and secrecy of the hillbilly ethic, including what he calls "the Appalachian honor code," stayed within him.

What is so striking about his book is the counterpoint between the utter dreadfulness of Vance's life, his persistent good humor in the face of it, and his perseverance in doing what he had to do to survive and get out of the Kentucky hollers in spite of monumental barriers. He watched his drug-addicted mother get hauled away by the police while the neighbors watched. Part of what he was fighting is summed up in the statement that "working class whites are the most pessimistic group in America."

The central, horrible, apparent characteristic of hillbilly life, according to Vance, is domestic violence. He is quite funny about some of it. His grandmother taught him how to fight effectively. He observes that even the best stepparents, of whom he had many, "take some getting used to."

One of the grim facts that he cites is that "the life expectancy of working-class white folks is going down." Another is that "Ohio Januaries are depressing enough as it is."

There are two problems here, nestling among what seem to me to be the truths about hillbillies. The first is that there are other groups in American society, in different parts of the country, whose situations are just as troubling, if not more so, than the problems of the hillbillies. They were outdoors for the most part, not jammed into crowded urban neighborhoods like many African-Americans and Hispanics and undocumented immigrants.

The other problem is that we all know from country songs that there is a definite predisposition for feeling sorry for oneself. Vance escapes these flaws through humor and a neat way with words. He calls the miserable experiences he and his sister had with their mother "adverse childhood experiences." He avoids the perils of what he calls "class tourism," looking at people he has to please like a sociologist.

His grandmother told him there was "no greater disloyalty than class betrayal." Vance has not betrayed his people at all in helping us, his readers, understand them better.

Dan Simpson is an associate editor at the Pittsburgh Post-Gazette.