Steven V. Roberts teaches journalism and politics at George Washington University.

Ted Peetz grew up in Milwaukee, a dedicated fan of the Green Bay Packers. He’s moved around a lot, but as George Dohrmann writes in “Superfans,” “wherever he went, Ted Peetz searched for them, for his people.” His fellow Packers Backers.

In Bowling Green, Ohio, Peetz frequented a sports bar where Packers fans drank only beer brewed by Miller, a Milwaukee company. In Las Vegas he found a hangout where “if the Packers scored you got a refill of whatever you were drinking.” And in Nashville, he joined the Music City Packers Backers because “he loved how they tailgated in the parking lot of the Scoreboard Bar & Grill, cooking brats and drinking before the bar even opened.”

Peetz embodies the core argument in Dohrmann’s lively book: To real sports fans, the team they root for is central to their identity. What they wear on their T-shirts and ball caps tells the world something important about them. The author quotes Harvard biologist Edward O. Wilson: “People must have a tribe. It gives them a name in addition to their own and social meaning in a chaotic world.”

One of the best chapters examines a variant on Wilson’s theme: Fans want to be part of a tribe and yet stand out at the same time. Teddy Kervin donned a banana costume one inebriated night at a Milwaukee Brewers game in 2012. A TV camera focused on Kervin, and suddenly he became a media star, the Rally Banana. He wore the costume to games for about a year, until one day, a young woman showed up in a similar get-up. “She is ripping me off,” Teddy fumed to himself. “How can she do this?” That overreaction, writes Dohrmann, “was because his ability to satisfy his need for distinctiveness was threatened, and people might view him (and he might view himself) as just another fan.”

Fandom often connects people to a specific place, not just a tribe. Sociologist Roger Aden studied supporters of the University of Nebraska football team and concluded, “For Nebraskans, both those living in the state and elsewhere, the team represented a way of life, an agrarian identity, the ‘ethos of the state.’­ ” Peetz says Aden’s work clarified his own emotions. “What he really wanted was to feel, even if only for a few hours, like he was back home, among people who shared his values and rituals,” writes Dohrmann.

Sports bars have been overshadowed, in a way, by online message boards that give far-flung fans instant access to one another. “For many people,” argues the author, “a fan group has usurped church membership or another community organization as the primary binding agent in their lives.” The risk is that these groups, floating in cyberspace, unmoored from the “values and rituals” Peetz prizes, can quickly turn virulent and vicious.

Journalist Charles Robinson learned this covering the NFL for Yahoo. He was often deluged with hateful emails, including one expressing the hope that “you, your family and your kids die a slow painful death.” Now Robinson says, “I think some fans are like drug addicts, and they are reacting as if someone is threatening their stash.”

Dohrmann insists that “being an extreme sports fan” makes many people “happier and (mentally) healthier individuals,” but his book is littered with examples of unhealthy behavior. The “addicts” Robinson describes not only worship their teams but despise their rivals, and psychologists worry that children can absorb “black and white” views of the world from “extreme” parents that are damaging and dangerous. “We are not born learning to hate,” says psychologist Susan Harter. “That has to be taught.”

This is a compelling book but with sizable flaws. It barely includes baseball (let alone NASCAR) and never once mentions Cubs or Cards, Red Sox or Yankees — franchises that have been eliciting strong loyalties for more than a century. Dohrmann has a fondness for modern teams like the Portland Timbers, a professional soccer club — fair enough. But he lacks a sense of history. He writes, almost sneeringly, that “fan bases are like ancient religions in that most are so old it is impossible to accurately trace their origin.”

But that is not true. Those origins are kept alive by myths and memories, faded photos and bubblegum cards and ticket stubs, collected and cherished over many generations. When the Cubs won the World Series in 2016, after a 108-year drought, countless fans visited the graves of their ancestors, leaving tokens and talismans that celebrated their shared history of devotion.

Yes, place and home are important factors in determining fan loyalty, but so are class and ethnicity — issues Dohrmann never touches. Catholic immigrants rooted for the Notre Dame football team as a way of becoming more American. Latino fans jammed Dodger Stadium every time Mexico-born pitcher Fernando Valenzuela took the mound.

This is also a very male-centric book. The only chapter devoted to women features a female-run website that advertises a “hottie of the week,” a well-muscled male athlete. I’m sure my 103-year-old friend Mary Cunningham, who watches every Atlanta Braves game in Sumter, S.C., doesn’t tune in for the hotties. Nor does Dohrmann discuss all the women who became sports fans as a way of relating to their fathers.

Still, his basic insight rings true: Being a sports fan means asserting an identity, connecting to a tribe and a time. When I was a child, my dad took me to Yankee Stadium several times a year, and we sat in a box along the first base line owned by his business associate. When I visit the stadium now, I think of my father, look at the first base line and give him a silent salute.

Superfans

Into the Heart of Obsessive Sports Fandom

By George Dohrmann

Ballantine. 202 pp. $27