As research has advanced, doctors have discovered that while football is the most fertile concussion breeding ground — with the outcome even earning its own pathological title: “gridiron dementia” — many other seemingly benign sports threaten the mental well-being of our children. American girls, for example, suffer three times more basketball concussions than boys, and more than twice as many soccer concussions. The beautiful game that soccer moms fancy for their dear offspring is not patty-cake; as brutal as our football may be, at least we don’t try to score by employing our heads as clubs.

Carroll and Rosner intersperse their more technical chapters (which are effectively written for the understanding of lay readers) with sad profiles of those who’ve sustained football concussions that have led to disability, shattered lives, insanity and early death. But, mercifully, substantive research has increased. Thanks to Chris Nowinksi, a former NFL player, who has been collecting brains from families of deceased players, pathologists are now able to study the damage. Moreover, because concussions are the “signature wound” of the Iraq and Afghanistan wars, considerably more attention has been paid to the subject. Even the NFL — which, with brain injuries, for so long mimicked the tobacco industry’s denial of cancer — has finally acknowledged the cruel reality that playing the sport is simply not amenable to maintaining intelligence.

Given the warrior mentality of those who scrimmage, it should not be surprising that players themselves are often most resistant to the sissifying of their game. Kevin Mawae, an all-pro center and head of the players’ union (a position that at least suggests he still possesses all his marbles) reacted to the new anti-concussion rules by grousing that “the skirts need to be taken off in the NFL offices.” Of course, Mawae has hard-boiled company. The National Hockey League has “dismissed any suggestion of penalizing head-on checks.” Nor is there evidence that either fans or TV networks are particularly sympathetic to reduced cerebral mayhem. During these hard times when the NFL might well be the most unthreatened business in America, the bloodlust factor appears to be a major bulwark of its unstoppable popularity.

As Carroll and Rosner emphasize, concussions are often undetectable. They aren’t just born from those bombastic crashes that television savors for its highlight reels. Cumulative jolts can ultimately inflict as much damage. One study found that counting both games and practices some college linemen endure up to 1,800 head hits per season. And because the human brain is not fully developed until its carrier body escorts it into its mid-20s, children are even more vulnerable. A total of almost 5 million boys play youth league and high school football — virtually all of them in this pigskin-lovin’ nation — and studies have shown that almost half of adolescent gridders have sustained concussions, a third of them on multiple occasions.

“The Concussion Crisis” is quite a devastating testament. It lays it all out and forces us to ponder how a civilized people can blithely accept an entertainment that does such damage to young men’s minds. I remember talking to an old boxer who pointed out to me that his sport was the only one where the participants didn’t want their sons to follow them into the game. Only the very desperate enter the ring, risking a trip down “queer street.” One lays “The Concussion Crisis” down wondering, likewise, where future American gridiron gladiators will come from; surely not from families who read this book.

is an author and NPR sports commentator; his most recent novel is a 1930s love story, “Bliss, Remembered.“