To fans, it’s been more than a soap opera

“It’s just a little piece of being back in my grandmother’s living room,’’ the Rowley resident says.

That connection will be lost, for many viewers, after the nation’s longest-running soap succumbs to the woes that have plagued daytime dramas for years: low ratings, changed viewing habits, an audience that no longer hits advertisers’ target demographic. Soaps are in peril, but they’re also deeply loved, and draw the kind of loyalty that’s seen in fans of comic books and professional wrestling, says Sam Ford, who taught a course on soaps last year in MIT’s Comparative Media Studies program.

“I think we have an inherent love of a story that’s bigger than we are,’’ Ford says.

Lois Angelo, 61, of Lexington, remembers watching at lunchtime as a first-grader - she liked watching grown-ups talk over coffee and kiss - then running a half-mile to get back to school on time. Years later, when she had kids of her own, “Guiding Light’’ was a source of bonding with her mother, sister, and cousins.

Collective viewing has a way of creating surrogate families, too. When news broke last spring that “Guiding Light’’ would be canceled, Newton resident Jennifer Roberts, 50, e-mailed her college roommate right away to reminisce about the times they’d watched together. Now, as the show wraps up its 72-year run with a flurry of marriages and miracle recoveries, Roberts finds herself hoping for long-term love for the star-crossed Josh and Reva - who have been married to each other three separate times - and lasting happiness for “friends that you know that you’re never going to hear from again.’’

“Guiding Light’’ first debuted in 1937 as a 15-minute radio serial, set in a fictional Chicago suburb called Five Points. The action later moved to Springfield, and the show first aired on television in 1952, switching to one-hour episodes in 1977.

Lemelin’s grandmother, Mary Dooling Reilly, started listening to the show on the radio and followed it to TV. She claimed that she watched for the fashion and the home decor, Lemelin recalls, but she discussed the plots for hours with friends, and celebrated characters’ milestones as if they were her own. When Reva and Josh got married in an over-the-top ’80s ceremony, Lemelin’s grandmother let her stay home from school to bake a wedding cake.

While love gained and lost has been a constant theme, “Guiding Light,’’ like all soaps, has also reflected the social issues roiling the nation, says Elana Levine, an associate professor at the University of Wisconsin-Milwaukee, who is writing a history of daytime soap operas. In the ’70s, Levine says, soaps saw a flurry of plots about rape, as the nation began to recognize rape as a crime.

More recently, soaps have experimented with portrayals of gay characters, from Luke and Noah on the CBS soap “As the World Turns’’ to Olivia and Natalia on “Guiding Light,’’ a lesbian couple preparing to raise their children together. (The characters have never shared an onscreen kiss, but the actresses plan to play another couple in a forthcoming Web-only show called “Venice.’’)

Soap viewership peaked in the 1970s and ’80s and then saw a steady ratings decline, as more women entered the workforce, cable TV offered more options, and cheaper-to-produce talk shows spread across the airwaves. Like many soaps, “Guiding Light’’ tried to stay relevant and cut costs. In February 2008, the soap abandoned its standing sets and began to shoot on-location, with hand-held cameras, in a New Jersey town. Other soaps have tried to woo young viewers with hot young characters, big cliffhangers, and computer-generated disaster sequences, Ford says.

But he thinks the shows might have a better chance of survival by focusing on core characters, pleasing the viewers they have, and encouraging new family traditions.

“The best way to get daughter and granddaughter is through Mom and Grandma,’’ Ford says. “And as you run Mom and Grandma off, you lose your ability to even get in front of daughter and granddaughter.’’

The family connection has kept Lemelin in touch with the workings of Springfield; she started keeping track of the show on the CBS website when her grandmother died in 2002, and recording the episodes in April when she learned that the show would be canceled. As she caught up on recent episodes this week, watching Reva play with both her grandchild and the baby she conceived after menopause, she shook her head at the absurdity and smiled.

For “the rational, logical . . . part of me, the professional person, it’s embarrassing,’’ Lemelin says. “But it’s the kid in me. It’s the ritual of watching. That familiar feeling of connecting.’’

Joanna Weiss can be reached at weiss@globe.com.