A comprehensive study by Swedish researchers, published this summer, found that 68 per cent of married men in their seventies and 56 per cent of married women in their seventies were having sex, with almost a third of those surveyed (31 per cent of men and 26 per cent of women) having it once a week.
More than 50 per cent of females in their mid-forties regularly go clubbing.
Sexually transmitted diseases among the over-45s have doubled in less than a decade. The rise is blamed on increasing use of the internet which is thought to encourage casual sex and of Viagra.
One in six 16-year-olds has had more than one sexual partner, according to a survey for Channel 4's Sex Education Show.
Growing numbers of Britain's twentysomethings are experiencing what sociologists now call a quarter-life crisis. A survey by the website Gumtree.com published in January 2008 found that almost seven million Britons in their twenties are deeply unhappy with their lives and under intense pressure to succeed in jobs, finances and relationships.
Older men are far more likely to be married than older women. Seventy per cent of men aged 65 and over live as part of a couple (according to the last census), whereas only 40 per cent of women do so. This reflects the tendency for women to outlive their husbands.
Eight out of 10 women in their twenties fear that they will never find a soulmate.
Attitudes towards love and sex between different age-groups have changed through the centuries. The current orthodoxy can be summed up by two rules: "half plus seven" (ie, it is acceptable to have a relationship with a younger person only if their age is at least seven years more than half your age); and "all paedophiles are monsters" (that is, any relationship involving someone under the age of 16 is utterly beyond the pale).
Other eras and societies have taken different views of age taboos. Child brides were common in many societies, and the mediaeval writer Hostensius argued that girls were ready for marriage at 12 and boys at 14.
As recently as the mid-1880s, the median legal age of consent in US states was 10. Georgia did not raise the age of consent from 10 to 14 until 1918.
In Ancient Greece, pederasty a same-sex relationship between an older man, known as the erastes, and a beardless boy, the paidika became a cultural ideal. The relationship would end once the boy reached puberty.
One in five teenage girls has kissed another girl in a sexual way according to a YouGov survey.
The age-group most likely to find love abroad are the over-sixties. Almost 10 per cent of holiday romances lead to wedding bells.
Over a third of over-fifties say they have sex between one and three times a week.
The average age for first marriages in England and Wales is 31 for men and 29 for women.
The first recorded use of the noun "paedophile" was in 1951.
Around 10 million people 20 per cent of the population say that they are not completely honest about their age.