Research has been conducted in the United States since the late 1960s. One study, based on an Internet questionnaire addressed to visitors of swinger-related sites, found swingers are happier in their relationships than the norm,.[1]

60% said that swinging improved their relationship; 1.7% said swinging made their relationship less happy. Approximately 50% of those who rated their relationship "very happy" before becoming swingers maintained their relationship had become happier. 90% of those with less happy relationships said swinging improved them.

Almost 70% of swingers claimed no problem with jealousy; approximately 25% admitted "I have difficulty controlling jealousy when swinging" as "somewhat true", while 6% said this was "yes, very much" true. Swingers rate themselves happier ("very happy": 59% of swingers compared to 32% of non-swingers) and their lives more "exciting" (76% of swingers compared to 54% of non-swingers) than non-swingers, by significantly large margins. There was no significant difference between responses of men and women, although more males (70%) than females completed the survey. This study which only polled self-identified swingers is of limited use to a broader application to the rest of society (external validity) due to self-selected sampling.

John Stossel produced an investigative news report into the swinging lifestyle. Stossel reported in 2005 that more than four million people were swingers, according to estimates by the Kinsey Institute and other researchers. He also cited Terry Gould's research, which concluded that "couples swing in order to not cheat on their partners." When Stossel asked swinging couples whether they worry their spouse will "find they like someone else better", one male replied, "People in the swinging community swing for a reason. They don't swing to go out and find a new wife;" a woman asserted, "It makes women more confident - that they are the ones in charge." Stossel interviewed 12 marriage counselors. According to Stossel, "not one of them said don't do it", though some said "getting sexual thrills outside of marriage can threaten a marriage". Nevertheless, swingers whom Stossel interviewed claimed "their marriages are stronger because they don't have affairs and they don't lie to each other."[17]

According to economic studies on swinging,[18] the information and communications technology revolution, together with improvements in medicine, has been effective in reducing some of the costs of swinging and hence in increasing the number of swingers. And the economic approaches which seem best suited to capture the empirical data are those based on the concept of hedonic adaptation. These approaches suggest that it is consistent with maximizing swingers’ strategy to begin from "soft" swinging and only later engage in "harder" swinging, and that also the search for ever new sexual experiences delays long-period hedonic adaptation and hence increases swingers’ long-period wellbeing. Both these theoretical predictions seem to find confirmation in the empirical data on swinger behaviour.