Marriage continues to be the living arrangement that confers the most happiness. But couples who live together without getting married can enjoy most of the benefits of marriage, and often have better self-esteem and flexibility in their living styles as well. And even the happiness gap between the two living arrangements is shrinking.
Intimacy produces tangible physical and well-being benefits, says Ben Karney, a professor of social psychology at UCLA. "Your body works better, your immune system functions better, and your body produces more antibodies," he says. "Study after study shows that people in good relationships live longer."
To prove this point, Ted Robles, a UCLA assistant psychology professor, has researched how dating couples respond to concerns about the strength of their relationships. During a first visit, the couples receive a small scrape on their arms and then talk about the problems in their relationship. They later come back for a second visit to discuss ways the relationship can be improved. Robles says the rates at which people's scrapes healed was directly related to their levels of concern about the health of their relationships. Emotions, in other words, drove their bodies' immune systems.
People also have different comfort levels with intimacy itself, Robles says. Unlike electrical charges, opposite intimacy types do not attract and may not produce the most healthful relationships. Chris Fraley, an associate professor of psychology at the University of Illinois, has produced an online questionnaire that can help couples measure their relative attachment styles.
Beyond physical and emotional ties, the lack of legal sanctions continues to be a defining difference between couples who marry and those who live together. But in recent years, notes sociologist Kelly Musick at Cornell University, advances in domestic partner rights and state recognition of same-sex marriages have narrowed this gap.
Today, so many unmarried people have decided to live together that attitudes and laws are changing. During the past 50 years, "the number of unmarried couples in America increased more than seventeen-fold," the National Marriage Project said in its 2011 annual report on the state of marriage.
"The young are much more inclined than their elders to view cohabitation without marriage and other new family forms—such as same-sex marriage and interracial marriage—in a positive light," the Pew Research Center said in a 2010 report. More than half of all adults between the ages of 30 and 49 said they had cohabited at some point in their lives. "In 2008, 6.2 million households were headed by people in cohabitating relationships," Pew added. "They included 565,000 same-sex couples."
Lisa Diamond, an associate psychology professor at the University of Utah, says the growth of same-sex relationships has expanded to include partnerships with little or no sexual activity. "There are tons of individuals that we know are having a long-term, same-sex relationship, where they wouldn't necessarily identify themselves as gay or lesbian," she says. "There are plenty of same-sex couples that are just living quiet lives and doing the same kinds of things that heterosexual couples do."
Because the accepted social roles of same-sex partners are so similar, Diamond explains, "same-sex couples seem to do a better job [than heterosexual couples] of maintaining equity ... and it is more important for them to have equity in their relationships."
While social attitudes have become more accepting of same-sex and other unmarried couples living together and even having children out of wedlock, people who describe themselves as conservative and religious told Pew they continue to have substantial reservations about the practice. And if the immediate families and friends of an unmarried couple do not support their living arrangement, it can replace needed support structures with opposition, which can create serious stresses. In other words, loving one another might not be enough.