You can tell a lot about how a family lives by their refrigerator -- not what’s inside, but what’s hanging on the outside.

If your fridge door is strewn with business cards, kids’ drawings, calendars, photos, schedules and other bits of minutiae, chances are, you’re living with big-time clutter -- not just in the kitchen, but everywhere in the house.

“The sheer volume of objects clinging to (your fridge) may indicate how much clutter can be found throughout your home,” reads a press release from UCLA about a study on the subject.

In 2012, researchers affiliated with UCLA’s Center on Everyday Lives of Families, or CELF, studied American families’ material possessions and lives. The results were compiled into a book called “Life at Home in the Twenty-First Century.”

The exhaustive study -- “an incredibly labor-intensive enterprise,” said lead author Jeanne Arnold -- looked into the daily lives of 32 dual-income, middle-class families in the Los Angeles area. The team made some interesting discoveries, including some situations that future homebuyers and remodelers should try to avoid.

For example, garages were so packed with household overflow that cars were parked in the driveway or on the street. No wonder a recent poll by the National Association of Home Builders found that both first-time and move-up buyers rated garage storage among their top five most essential features.

Garages do provide storage, of course, but often not for automobiles. Only 1 in 4 of the garages in the CELF study could be used for cars because they were so packed with other stuff. This, even though keeping a car out of the weather is one of the best ways to extend its life.

The book labels garages “the new junk drawer.” Many families said they were parking their stuff in their garages until they could decide what to do with it, but plans to sell items online or at a garage sale rarely materialized.

For the study, CELF sent archaeologists, anthropologists and other social scientists to systematically study families’ home lives. The resulting book presents what co-author Elinor Ochs, an anthropologist and CELF’s director, says is a troubling picture of costly space that often goes unused.

Here’s a brief look at some of the other findings.

-- One of the most common renovations the 32 homeowners undertook was upgrading their master bedrooms, usually with the addition of an adjoining bathroom. Often designed and decorated to evoke luxury hotels, these private spaces were envisioned as refuges from the hustle and bustle of family life.

Yet researchers found that other than for sleeping and bathing, these spaces were rarely used, even though the cost to upgrade them often ran above $80,000 -- an amount that approached or exceeded the homeowners’ combined annual salaries. Families gladly spent that money, while ignoring “vexing pinch-points” such as crowded kitchens.

-- Even in the L.A. region, with its favorable year-round weather, families hardly used their yards. Nearly 3 out of 4 sets of parents spent no leisure time out back, and about half their kids didn’t, either. “They could not manage to carve out time to relax, play, eat, read or swim, despite the presence of such pricey features as built-in pools, spas, dining sets and lounges,” the researchers found.

In other words, those major expenses turned out to be mostly for looks.

Arnold said that families are “very sedentary at home. The ideal of indoor-outdoor living -- the California dream since the 1950s -- seems increasingly out of reach.”

-- The volume of these families’ possessions was sometimes overwhelming: One family actually stored their dirty clothes in an unused shower. And these messes affected moms and dads very differently.

“Mothers who lamented messy or cluttered rooms or unfinished remodeling projects when describing their homes were more likely to have elevated levels of stress hormones,” read a news release, while fathers often mentioned no messes at all.

“They were unaffected physiologically,” said Arnold. “The differences between parents and their comfort level about clutter and its long-term impact on well-being are pretty astonishing.”

-- Just 3 percent of the world’s children live in the United States, but their families buy more than 40 percent of the toys purchased globally. Most homes in the study had at least 100 toys on display, and several had more than 250. And countless other toys were stashed in closets or under beds.

-- Shopping at big-box stores leads to stockpiling, which compounds clutter. Nearly half the families had a second refrigerator or freezer to accommodate extra food, and a few even had a third.

“I don’t think Americans intend to collect so much,” says co-author Anthony Graesch, an assistant professor of anthropology at Connecticut College. “But we’re really bad at ridding our homes of old possessions before buying new stuff.”

The price was recently slashed by $1 million for Bill Murray’s mansion from the comedy “Zombieland.” Owner Lee Najjar is now asking just $13.8 million for the property.

The 2009 film was a spoof of the horror genre. The film’s stars, including Jesse Eisenberg, Emma Stone, and Woody Harrelson, are the last known survivors of a zombie apocalypse. It takes place all over the make-believe map. But before they wind up at the supposedly zombie-free Pacific Playland amusement park, they visit Murray’s house in Hollywood.

Only the 33,000 square-foot mansion isn’t in Hollywood. It isn’t even in California. It’s in Atlanta, sitting on two acres on West Paces Ferry Road in the ritzy Buckhead area. And with the approach of Halloween, that annual homage to ghosts and goblins, it causes one to wonder about other scary filmdom houses and their actual locations.

Places like the house in “Nightmare on Elm Street,” the 1984 slasher film by Wes Craven. It featured Johnny Depp in his movie debut, as well as Robert Englund as the razor-gloved killer, Freddy Krueger. If the three-bedroom house in the movie could talk, it would scream bloody murder. And it would tell you it’s not located in the fictional town of Springwood, Ohio, but rather on Genesee Avenue in Los Angeles.

The townhouse featured in “The Exorcist” was in Georgetown, a ritzy section in the nation’s capital. The movie about demonic possession was released in 1973, but just the thought of Linda Blair’s head turning 360 degrees still brings shivers to the spine.

The film was based on a book by William Peter Blatty, which itself was based on an actual exorcism. But the ritual didn’t take place on Prospect Street NW, where the movie was made, but rather in a long-lost residence in the nearby Maryland suburb of Mount Rainier.

In the video for “Thriller” -- often called the greatest music video of all time -- Michael Jackson and his ghoulish friends break into song and dance, then he chases his date into a Victorian house. The video makes no mention of its location, but listen up, superfans: The house is on Carroll Avenue in Los Angeles.

Not far away in Altadena stands the Omega Beta Zeta House from “Scream 2,” another Wes Craven slasher. The 6,500-square-foot house on East Crary Street sits on 1.5 acres and has seven bedrooms and four full bathrooms.

Across the continent, folks who remember “Rosemary’s Baby,” Roman Polanski’s 1968 horror film, can find Rosemary Woodhouse’s apartment building on West 72nd Street in New York City. The building, called the Dakota, is probably better remembered as the place where Beatle John Lennon lived, and was killed.

“Halloween,” a 1978 film directed by John Carpenter and featuring Jamie Lee Curtis in her film debut, was set in the fictional Midwestern town of Haddonfield, Illinois. But white-masked murderer Michael Myers actually shot scenes in a five-bedroom house on North Orange Grove Avenue in Los Angeles.

In the TV series “Buffy the Vampire Slayer” (adapted from the 1992 movie of the same name), high-schooler Buffy Summers must defend the world against vampires. Exterior shots of her house showed a palm-studded four-bedroom house on Cota Avenue in Torrance, California, just down the street from Torrance High -- aka Buffy’s school, Sunnydale.

The eerie-looking “witch’s house” in the 1957 film “The Undead” was built during the 1920s on a studio lot as a dressing room and office, before being moved to Walden Drive in Beverly Hills to be used as a private residence. A longtime resident used to dress as a witch to hand out candy every Halloween.

The place featured in the 1959 B-movie “House on Haunted Hill” might just be the only house of any architectural significance to ever be featured in a horror film. In the movie, Vincent Price pays guests to stay one night in a house where the ceiling drips blood. But the only thing that really drips from this place is history: The exterior shots were of Frank Lloyd Wright’s 1924 masterpiece Ennis House in L.A.’s Los Feliz neighborhood.

In “What Ever Happened to Baby Jane?,” a psychological thriller starring Bette Davis and Joan Crawford, the five-bedroom house used for exterior shots can be found on South McCadden Place in Los Angeles. The final scene on the beach, however, was filmed in Malibu.

“Dead Again,” a 1991 reincarnation film, might come back to haunt its actors, among them Emma Thompson and Andy Garcia, as well as its filming location on Broadview Terrace in L.A.

Some realty professionals speak out of both sides of their mouths, according to new research. A recent study found that some agents, teams and brokers profess to being highly knowledgeable about their local markets, but cast a far wider net when marketing themselves.

“The headline for the survey could very well read, ‘Agents, teams and brokers say one thing, do another,’” says the WAV Group, a consulting firm, in a release. WAV Group conducted the study for zavvie, a Colorado-based technology firm.

In that zavvie sells an online marketing platform that allows agents to dominate their local areas, the study’s results could be considered self-serving. But Kevin Hawkins, president of WAV’s communications affiliate, says the data was not manipulated in any way by, or for, zavvie.

“They sponsored the survey and paid for it, but they did not have anything to do with” the results, he says.

Besides, Hawkins adds, numerous companies offer hyperlocal marketing programs, not just zavvie. The survey serves them all, not just WAV’s client.

As Hawkins sees it, the hyperlocal movement has taken over a number of businesses already -- the farm-to-table crusade in the restaurant field, for example -- and many consumers are enthusiastic about the trend. Yet real estate is lagging.

“Real estate has always been about ‘local, local, local,’ but agents tend to cast a wider net,” Hawkins says. “You can’t be an ‘expert’ that far and wide. The ideal market in the real estate world is about 3,000 houses. That’s what’s needed to create a sustainable, ongoing business.”

In what is said to be the first-ever survey of its kind, researchers found that a nearly unanimous 95 percent of agents, teams, broker-owners and realty executives say local market knowledge is either “very important” or “extremely important” to their clients. But the poll found a “great disconnect” between that sentiment and what realty pros are actually practicing in their marketing activities.

Says zavvie CEO and co-founder Lane Hornung: “The survey clearly shows their marketing efforts are not consistent with hyperlocal being an actual priority.”

When asked how many respondents actually specialize in neighborhoods, just 12 percent -- about 1 in 8 -- raised their hands.

Hornung suggested that agents and teams who want to go local should focus their marketing activities specifically on a neighborhood or group of neighborhoods, which the zavvie exec defined as about 10,000 people -- or roughly, as Hawkins mentioned, 3,000 houses.

“In fact, the study found that most real estate professionals are doing the exact opposite,” says Hornung. “They are casting the largest net, trying to draw their marketing circle as broad as possible.”

The survey was returned by some 425 respondents, including 350 practicing professionals. Agents accounted for more than half the responses, while broker-owners and company executives made up about a third.

More than 3 in 5 agents and teams reported specializing in a large regional or metro area, a finding that Stefan Peterson, zavvie’s COO and other co-founder, called an “oxymoron.”

“You can’t specialize in a city or a town. It’s just too big of an area geographically (for one person) to be a ‘go-to expert’ that knows every single home in that size of a market,” he said. “Yet that’s what folks are claiming.”

More evidence of this behavioral disconnect between what agents say and what they actually do: Few agents and teams reported using marketing tools that let them share their local expertise -- tools such as a blog (7 percent used one), a neighborhood website (15 percent) or Nextdoor, a private social network serving local communities (15 percent).

“All of these are core tools of a typical hyperlocal agent’s marketing system,” said Peterson.

At the same time, 38 percent said they were “extremely knowledgeable” and 42 percent more were “very knowledgeable” about local goings-on and changes that impact the real estate market.

Peterson says that this finding begs the question: “If all of these agents, teams and brokerages have all this local knowledge, how is anyone going to know it if they are not sharing it?”