Drs. Geoffrey L. Greif and Kathleen Holtz Deal

Drs. Geoffrey L. Greif and Kathleen Holtz Deal, both of the University of Maryland School of Social Work, have written a book called "Two Plus Two Couples and Their Couple Friendships." (Barbara Haddock Taylor, Baltimore Sun / January 9, 2012)

What if Ricky Ricardo didn't love Lucy?

Unthinkable as that might be, new research by two professors from the University of Maryland School of Social Work suggests that the secret to a long and happy marriage might live nearby, like the Ricardos' landlords, Fred and Ethel Mertz.

According to "Two Plus Two: Couples and Their Couples Friendships" by Geoffrey Greif and Kathleen Holtz Deal, a close-knit foursome can strengthen both sets of marriages. The authors say their book, which was recently released by Routledge press, is the first scholarly account of shared friendships that are specifically between couples.

Both Greif and Deal are involved in long-term marriages (he for 36 years, she for 43). Both say that their four-way friendships have bolstered their commitments to their own spouses.

"There are two couples with whom my husband, Dave, and I are particularly simpatico," Deal says.

"These people have been a huge influence on my life. I see them more frequently than I do my siblings. We've vacationed together. We can talk about anything we want to. We've been through sad times and good times."

For their research, the two professors interviewed 426 people between 2008 and 2010, including 123 couples, though they stop short of claiming that their findings are representative of couples in the U.S.

For instance, only heterosexual couples are included in "Two Plus Two." The authors say there are important differences between same-sex and opposite-sex friendships and they couldn't cover both topics in the same book.

Greif and Deal also acknowledge that the couples in the study weren't selected randomly, which could bias the study's results.

For instance, interviews were restricted to stable, happy couples. In addition, most interview subjects lived on the East Coast, and the sample size didn't include as many Latinos as Greif and Deal would have wished.

As a result, "Two by Two" reaches relatively few cast-in-concrete conclusions. Rather, it paints an intimate portrait of how real-life couples tackle various issues in their paired friendships. The authors think their book draws a useful portrait of how couples friendships tend to function in marriages that work.

The book chronicles the quandary faced by Stacey Ishman, 42, and Jim McCarthy, 49, of Baltimore County. (Identities in the book were changed to protect the anonymity of the research subjects. So, in "Two Plus Two" Ishman, a pediatric surgeon, and McCarthy, who works in sales and is a stay-at-home dad, are called "Tracy" and "John.")

The two have been married for nearly a decade and are frustrated by their current inability to form more intimate couple friendships. They want to meet more duos like themselves, couples who married late and have young children roughly the age of their own two boys: 6-year-old Ben and 2-year-old David.

"We'd love to have a group of really smart, nice couple friends who have the same perspective we do," Ishman says.

"But they aren't easy to find. People our age usually have kids who are older, and they're talking about issues relating to college and high school. We're still dealing with 2-year-old tantrums."

Most academic research currently being done in the U.S. homes in on dysfunction, says Greif, who has written several previous books and writes a blog for Psychology Today magazine. In contrast, he and Deal assigned themselves the task of ferreting out the factors that result in success.

"We were interested in a strength-based perspective," Greif says. "We wanted to focus on people who are doing things right. Maybe we can learn something from them."

Ishman and McCarthy say that socializing with other couples brings out the best parts of their partners' personalities. After an outing with a compatible duo, husband and wife perceive one another in a rosier light.

"Jim has a very dry wit that I love," Ishman says. "He's fun, and people enjoy spending time with him."