Women are more satisfied if sex is accompanied by love and commitment, a new study finds.

Researchers from Penn State University conducted 90-minute interviews with 95 heterosexual women who lived in Pennsylvania, New Jersey and New York between September 2008 and July 2011. All women were aged between 20 and 65 years.

Analysts noted that 53 percent of the participants said love was necessary for maximum satisfaction in both sexual relationships and marriage. Only 20 percent said love was unnecessary in a sexual relationship.

"Women said that they connected love with sex and that love actually enhanced the physical experience of sex," said Beth Montemurro, lead author of the study, in a press statement. "When women feel love, they may feel greater sexual agency because they not only trust their partners but because they feel that it is OK to have sex when love is present."

Older women in the study said that the relation between sex, love and marriage was important to them throughout their lives and not just in certain eras. Researchers also found many women considered sex to be an expression of love.

Despite many becoming liberal about women's sexual desires, women and girls that indulge in sex outside committed relations are looked down upon, even today.

"On one hand, the media may seem to show that casual sex is OK, but at the same time, movies and television, especially, tend to portray women who are having sex outside of relationships negatively," said Montemurro. "For the women I interviewed, they seemed to say you need love in sex and you need sex in marriage."

Findings were presented at the annual meeting of the American Sociological Association. The project was funded by the Career Development Professorship and the Rubin Fund.