French women are becoming increasingly assertive in their sexual habits, while one-in-five younger French men "has no interest in sex", according to one of the most comprehensive surveys of the nation's love lives.

Women now have more than twice as many partners as they did in the 1970s, according to the study by the French Aids research agency, which is backed by the government.

One of the biggest changes in recent years  was that male and female sexual behavior had become increasingly similar.

The proportion of French women who claim to have had only one partner has dropped from 68 per cent in 1970, to 43 per cent in 1992 and 34 per cent in 2006. A woman's average number of partners has risen from under two in 1970 to over five today, while a man's has remained the same for four decades, almost 13.

French women's first experience of sex is now almost as early as that of the opposite sex: in 1950 there was a two-year difference, but the gap has narrowed to four months, to around 17 and a half. Meanwhile, more women remain sexually active for longer than previously: nine-out-of-10 women over 50 are sexually active today, compared to just 50 per cent of that age group in 1970.

The good old dichotomy (male predators, females patiently awaiting the warrior's return in front of the cave entrance) is in big trouble

Female sexual emancipation has been a hot topic in France ever since President Nicolas Sarkozy met Carla Bruni, the Italian model and singer.

Ms Bruni recently declared monogamy "terribly boring" and spoke in relaxed fashion about her numerous past conquests, including Mick Jagger and Eric Clapton.

At the same time, she reinforced old stereotypes that link status and virility, by reportedly declaring: "I want a man with nuclear power."

Despite the changes in female behavior some things have not altered in 40 years. Men found it easier than women to disassociate sex from love, but this was due to nurture rather than nature. Young women are still educated to consider their entrance into sexuality as a sentimental-relationship experience.

One of the more surprising findings was that one-in-five French men aged between 18 and 24 "manifests no interest in sexuality while abstinence rates for men under 35 was twice as high as for women.

the French had fewer sexual taboos and inhibitions than before, but were more anxious about lovemaking.