The Janus Report on Sexual Behaviour, compiled by the husband- and-wife team of Samuel and Cynthia Janus, goes a step further to suggest that the United States has just undergone a 'second sexual revolution'. The first was the liberation of the collective libido in the Sixties and early Seventies. Now it is a liberation from religious and political scruples.
Doubtless the report - all 430 pages of it, based on interviews made over the nine years with nearly 8,000 Americans - will take its place in libraries and sociology departments alongside the pioneering works of Alfred Kinsey in the Fifties, Masters and Johnson a decade later, and the British Wellcome Report last year.
Perhaps this is why the Janus report's publication earlier this month has not set America quivering. But the fascination level remains predictably high.
The report offers a broad seam of data, ranging from the unsurprising to the simply unbelievable. Take, for instance, the assertion that while 37 per cent of men aged 18 to 26 say they have sex 'a few times a week', for men aged 65 and over, the figure is 38 per cent. That is likely to come as a surprise to members of both age groups. Older people are, apparently, masturbating more than teenagers, too.
Then there is the news that 10 per cent of men claimed to have had sexual relations with 100 or more partners. A little macho-exaggeration, perhaps? But odder still: 15 per cent of males on the West Coast said they had passed the 100-partner mark, but only 1 per cent of Midwesterners made such a claim.
To support their basic conclusion that sex is back in fashion, the Januses - he is a sex counsellor and she is a doctor and author - tell us that 62 per cent of men and 68 per cent of women between 18 and 26 increased their sexual activity over the past three years. Although 80 per cent of men and women said they remained worried about Aids, most added that they saw it primarily as a risk faced by the poor and gay people.
In contrast to some of the earlier studies, the Janus Report gives little space to homosexual practices or the increased use of condoms. We are told, however, that 6 per cent of American men have enjoyed cross-dressing (the ghost of J Edgar Hoover can relax) while 14 per cent have engaged in sadomasochistic activities. The Januses found that 22 per cent of men and 17 per cent of women have had at least one gay or lesbian experience; the Wellcome survey surprised some by saying that only 6 per cent of men had had some gay contact.
Some statistics may give cause for worry, including the discovery of an increase in sex between pre-teenagers. Meanwhile, 45 per cent of women said they had been sexually harassed at work, while 11 per cent of men and 23 per cent of women reported having been sexually molested as a child, mostly by close family members.
On the alleged separation of sexual practice from religious or political beliefs, the authors write that 'everything from the age of sexual initiation into emotional/sexual commitment seems left up to the individual. Where once parents and religion provided markers and guidelines, peers and the media now provide a confusing and contradictory landscape'.
Plenty of evidence is provided to back up this theory. More of those who called themselves 'very religious', for instance, associated sexual pleasure with pain than those who were non-religious. And ultraconservatives appear much more hung up on achieving simultaneous orgasm during intercourse than ultra-liberals.
Meanwhile, the very religious and Republicans are more likely to cheat on their wives. Of the very religious, 31 per cent had cheated on their mates at least once. In fact, the report strikes a sharp blow to the Republican Party, which fought the last election on a platform of 'family values'.
Consider this from one of the report's subjects, a 'hostess/demonstrator', aged 31: 'I love doing conventions, particularly the Republicans. Not only the Republicans; almost any conservative group . . . Many come to these functions without their wives, but even if they have their wives, they sneak around and serve up sex action like you wouldn't believe.' Did Marilyn Quayle know?
'The Janus Report on Sexual Behaviour' is published in Britain on Thursday by John Wiley ( pounds 16.95).