According to the results of a global survey older men are more satisfied with their sex lives than their female equivalents.
The survey found that the vast majority of people who are married or who have a partner remain sexually active throughout the second half of their lives and age had little effect on sexual well-being.
The study involved surveying 27,500 people between the ages of 40 and 80, including equal numbers of men and women across 29 countries.
The study's intention was to draw out people's personal views of the role of sex in their relationships with partners.
It included questions about how physically or emotionally satisfying their relationships were and how important sex was to them.
They were also asked about their overall happiness; physical and mental health circumstances, including sexual dysfunction; their attitudes toward sex; and their attitudes toward various social and demographic factors, including age, education, income and religious affiliation.
This is the first large-scale international study to include large numbers of respondents from diverse religious traditions, including Christian, Jewish, Muslim, Buddhist and other Asian religions, and atheists.
A particular focus was the impact of aging, health conditions and socio-cultural context on sexual well-being.
According to the international team of researchers factors such as health problems or depression had a substantial impact on a person's sex life.
The study found that people reported the greatest sexual satisfaction in four countries, led by Austria, and followed by the United States, Spain and Canada.
At the low end of satisfaction were Japan and Taiwan. Countries such as Turkey, Egypt and Algeria were in the middle.
The survey examined how they viewed their sex lives, their health, and their happiness and found that for a greater proportion of people in Europe, North America, and Australia, where men and women have equality in their relationships, sex was an enjoyable experience both physically and emotionally.
The research indicated that fewer people reported satisfying sex lives where men have a dominant status over women, such as nations in East Asia, and the Middle East, and in poorer countries, but the gender gap of 10 points remained consistent across the world.
On average men reported higher levels of satisfaction with their sex lives than women.
Lead author, Edward Laumann, the George Herbert Meade Distinguished Service Professor in Sociology at the University of Chicago, says in the survey there was a bias towards married people who were prepared to talk about their sex lives, and towards urban populations in less-developed nations.
Laumann says procreation is the rationale for sex, and pleasure is not "part of the story" in sexually conservative cultures in the Far East such as China, Indonesia, Japan, Taiwan, and Thailand.
He says many women class sex as dirty, as a duty, and as something they endure and often stop having after age 50.
As many as two-thirds of adults in Western nations however reported they were very or extremely satisfied with their sex lives but some countries appeared happier than others.
Austrians at the top of the league with about four out of five middle-aged to older Austrians, rated their sex lives highly, while considerably fewer adults in France and Sweden shared that satisfaction.
In the United States, about three-quarters of men and two-thirds of women are reportedly very satisfied with the physical and emotional aspects of their sex lives, while in Japan, just 18 percent of the men and 10 percent of the women were positive about their sex lives.
In Taiwan, only 7 percent of the women said sex was very important in their lives and Laumann says the survey showed that satisfying sex is not the same as a satisfying sexual relationship.
People who are dating he says have higher levels of sexual satisfaction than married couples, but when they think the relationship is temporary, they do not feel as positive about sex.
An article on the survey, titled "A Cross-National Study of Subjective Sexual Well-Being Among Older Women and Men: Findings from the Global Study of Sexual Attitudes and Behaviors," is published in the April issue of the journal Archives of Sexual Behavior.