The number of adults engaging in at least one same-sex experience has increased up to two times since the 1990s, according to a study published on June 1 in the journal Archives of Sexual Behavior. In just over 25 years in the US, from 4.5 percent, about 8.2 percent of men had sex with at least one man and from 3.6 percent, 8.7 percent of women had sex with another woman.

The study also found that about 7.7 percent of adults have sex with both men and women, higher than the 3.1 percent recorded in 1990. In the 2010s, those between the ages of 18 and 29, about 7.5 percent men and 12.2 percent women, claimed to have sex with the same sex.

Women were more likely to engage in same-sex experience when they are young. On the other hand, age is not a factor for men in their same-sex encounters.

Gay couple. Photo from SurrogateFinder

The findings also reveal that same-sex relations acceptance has increased. Between 1973 and 1990, the same-sex sexuality acceptance rose from 11 percent to 13 percent. By 2014, the percentage has risen up to 49 percent among all adults, with millennials being the most acceptable, about 63 percent.

These behavior and attitude changes may be due to social and media reasons. Overall, the researchers believe that Americans do not care about social norms as they used to and instead care more about fulfilling their wants.

“These trends are another piece of evidence that American culture has become more individualistic and more focused on the self and on equality,” says Jean Twenge, a professor of psychology at San Diego State University. “Without the strict social rules common in the past, Americans now feel more free to have sexual experiences they desire.”

The researchers from the San Diego State University, the Florida Atlantic University, and the Widener University studied the data of more than 30,000 adults in the US from the General Social Survey. It is a survey that inquired about the participants’ perception towards same-sex sexual behavior and sexual partners since 1973 and 1989, respectively.