A new study says that having a couple to double date with can improve the happiness of one's own relationship.
For the study, researchers from the University of Maryland interviewed 123 couples, 122 individuals in relationships, but who were questioned alone and 58 divorced individuals.
On an average, couples had about five "couple friends" they spent time with. When asked how important these friendships were, 40 percent of respondents said they were "very important" and 39 percent said "somewhat important".
The researchers found that when couples indicated they agreed on how to divvy up their time between others and themselves, they were more likely to also say they had a happy marriage or relationship.
For different people, these "couple" relationships had different meanings.
"Couples are looking for different things in their couple friendships - we found there are 'fun-sharing' and 'emotion-sharing' couples," LiveScience quoted Geoffery Greif, the study leader as saying.
Many couple friendships seemed to start out as a one-partner friendship that blossomed into a foursome. For some, though, finding couple friends was difficult, with lives busy with work and family.
"Sometimes couples go to Craigslist- our sampling of Craigslist websites in different cities did turn up groups like book clubs for couples, environmental groups, hikers, cooking, wine clubs, etc.," Greif said.
"At the same time, we quote a couple at the beginning of the first chapter who advertised for friends in a small town and got responses from couples that wanted to swing. They removed their ad," he said.
The researchers concluded that healthy couple friendships make a marriage more fulfilling and exciting for several reasons - by increasing partners' attraction to each other, providing a greater understanding of the opposite sex, and allowing partners to observe ways that other couples interact and negotiate differences.
"With a great couple friendship, you get to see your partner at her/his best.
"He or she is having fun, interacting in a loving and supportive way with another couple as well as with the partner," he added.
The study has been published as part of the book 'Two Plus Two: Couples and Their Couple Friendships' by Greif and Kathleen Holtz Deal.