Marriage and cohabitation featureAs marriage rates have declined, the share of U.S. adults who have ever lived with an unmarried partner has risen. Amid these changes, most Americans find it acceptable for unmarried couples to live together, even for those who don’t plan to get married, according to a new Pew Research Center study. Still, a narrow majority sees societal benefits in marriage. The study also explores the experiences of adults who are married and those who are living with a partner, finding that married adults express higher levels of relationship satisfaction and trust in their partner than do those who are cohabiting.

Here are seven key findings from the report:

1 A larger share of adults have cohabited than have been married. It's now more common to have cohabited than to have marriedAmong adults ages 18 to 44, 59% have lived with an unmarried partner at some point in their lives, while 50% have ever been married, according to Pew Research Center analysis of the National Survey of Family Growth. By contrast, in 2002, 54% of adults in this age group had ever cohabited and 60% had ever married. Most adults ages 18 to 44 who have cohabited (62%) have only ever lived with one partner, but 38% have had two or more partners over the course of their life.

Looking at present relationships, 53% of adults ages 18 and older are currently married, down from 58% in 1995, according to data from the Current Population Survey. Over the same period, the share of Americans who are living with an unmarried partner has risen from 3% to 7%.

2 Most Americans (69%) say cohabitation is acceptable even if a couple doesn’t plan to get married. Another 16% say it’s acceptable, but only if the couple plans to marry, and 14% say it’s never acceptable for an unmarried couple to live together.

Wide acceptance of cohabitation, even as many Americans see societal benefits in marriageYounger adults are more likely than their older counterparts to find it acceptable for an unmarried couple to live together. About eight-in-ten adults younger than age 30 (78%) say that cohabitation is acceptable even if the couple doesn’t plan to marry, compared with 71% of those ages 30 to 49, 65% of those 50 to 64 and 63% of those 65 and older.

While most Americans say cohabitation is acceptable, many see societal benefits in marriage. A narrow majority of Americans (53%) say that society is better off if couples who want to stay together long-term eventually get married, while 46% say society is just as well off if they decide not to marry.

3 Married adults have higher levels of relationship satisfaction and trust than those living with a partner. Married adults are more likely than those who are living with a partner to say things are going very well in their relationship (58% vs. 41%). They also express higher levels of satisfaction with specific aspects of their relationship, including the way household chores are divided between them and their spouse or partner, how well their spouse or partner balances work and personal life, how well they and their spouse or partner communicate, and their spouse’s or partner’s approach to parenting (among those with children younger than 18 in the household). When it comes to their sex lives, however, similar shares of married and cohabiting adults (about a third) say they are very satisfied.Married adults have a more positive view of how things are going in their relationship

Married adults are also more likely than those who are cohabiting to say they have a great deal of trust in their spouse or partner to be faithful to them, act in their best interest, always tell them the truth and handle money responsibly.

The link between marriage (vs. cohabitation) and higher levels of relationship satisfaction and trust remains even after controlling for demographic differences between married and cohabiting adults (such as gender, age, race, religious affiliation and educational attainment).

4 Many cohabiting adults see living together as a step toward marriage. About two-thirds of married adults (66%) who lived with their spouse before they were married (and who were not yet engaged when they moved in together) say they saw cohabitation as a step toward marriage. Among cohabiting adults who were not engaged when they moved in with their partner, 44% say they saw living together as a step toward marriage.

Non-engaged cohabiters with no college experience less likely to see cohabitation as a step toward marriageAmong cohabiters who are not currently engaged, half of those with a bachelor’s degree or more education and 43% of those with some college experience say they saw moving in with their partner as step toward marriage. Smaller shares of those with a high school diploma or less education (28%) say the same.

When U.S. adults are asked about the impact that living together first might have on the success of a couple’s marriage, roughly half (48%) say that, compared with couples who don’t live together before marriage, couples who do live together first have a better chance of having a successful marriage. Another 13% say they have a worse chance and 38% say it doesn’t make much difference. Younger adults are particularly likely to see cohabitation as a path to a successful marriage: 63% of adults younger than 30 say couples who live together before marriage have a better chance at a successful marriage, compared with 52% of those ages 30 to 49, 42% of those 50 to 64 and 37% of those 65 and older.

5 About four-in-ten cohabiting adults cite finances (38%) and convenience (37%) as major reasons they moved in with their partner. By comparison, just 13% of married adults cite finances and 10% cite convenience as major reasons why they decided to get married.

Among both married and cohabiting adults, love and companionship top the list of reasons why they decided to get married or to move in with their partner. Nine-in-ten married adults and 73% of cohabiting adults say love was a major factor in their decision. About two-thirds of married adults and 61% of cohabiting adults cite companionship as a major factor.

Cohabiting women are more likely than cohabiting men to say love and wanting to have children someday were major reasons why they moved in with their partner. For example, 80% of cohabiting women cite love as a major factor, compared with 63% of cohabiting men. No gender differences are evident on this question among married adults.

6 Many non-engaged cohabiters who want to get married someday cite finances as a reason why they’re not engaged or married. About three-in-ten cohabiting adults who are not engaged but say they would like to get married someday cite their partner’s (29%) or their own (27%) lack of financial readiness as a major reason why they’re not engaged or married to their current partner. About a quarter (24%) say their partner not being ready financially is a minor reason, and 29% say the same about their own finances.

Roughly four-in-ten (44%) say not being far enough along in their job or career is at least a minor reason why they’re not engaged or married to their partner. Cohabiters who are not engaged but want to get married someday are more likely to cite their partner not being ready (26%), rather than themselves (14%), as a major reason they’re not engaged or married.

7 Most Americans favor allowing unmarried couples to have the same legal rights as married couples. Roughly two-thirds of adults (65%) say they favor allowing unmarried couples to enter into legal agreements that would give them the same rights as married couples when it comes to things like health insurance, inheritance or tax benefits, while 34% oppose this.

About two-thirds favor allowing unmarried couples to have the same legal rights as married couplesDemocrats and those who lean toward the Democratic Party are far more likely than Republicans and Republican leaners to favor allowing these types of legal agreements for unmarried couples. About three-quarters of Democrats (77%) favor this, including 45% who strongly favor it. By contrast, Republicans are about evenly split: 50% favor and 49% oppose this. Party differences are also evident in views concerning the acceptability of cohabitation, the societal benefits of marriage, the impact of cohabitation on the success of a couple’s marriage and whether cohabiting and married couples can raise children equally well.

Note: See full topline results and methodology.

Nikki Graf  is a former research associate focusing on social and demographic trends at Pew Research Center.