IT first happened more than a million years ago. Today people all over the globe do it at least once a day - and there's no sign of a let-up. It is, of course, the kiss - the activity that adolescents around the world anticipate and agonise over, which film directors now dismiss as passe and which advertisers still use to sell anything from perfume to cooking oil. For all the studies and research into the history of man, precious few facts are known about the kiss and where it came from. No one, for example, actually knows where or when the first kiss was consummated. If historians could single out one nation or even one region and prove that the kiss was first known in one place, then we could have a good clue as to how long smooching has been going on. The trouble is that an enormous amount of national pride rests on the matter. Like the invention of the wheel or the discovery of fire, few nations care to admit they picked up their pecking points from other people. French and Italian men have long claimed to be the best kissers. But that may well be wishful thinking. South American women and California girls are also reputed to be world-class kissers. But recent evidence suggests that Russian girls, surprisingly, may be the most skilled kissers of all. One problem in tracing the trail of the kiss back to its roots is that we are not sure whether the act is a natural one or a learned response. If it is a natural act, the kiss probably was born in many places around the same time. But if it was a learned art - like swimming or speaking - then somebody, somewhere actually did get the idea first and then everyone else learned the new fad from him (or her). According to anthropologists, the kiss in one form or another is very much a part of the natural play of animals. They say that as man became more advanced, he still retained several animal-type traits, among them body hair, canine teeth and last, but not least, the kiss. While the theory that kissing developed in the natural course of events sounds convincing, many historians point out that if the kiss is a natural habit of mankind, why is it that the style of kissing varies greatly from place to place? Eskimos, for example, kiss by briskly rubbing their noses together, while the Polynesian islanders of Tahiti, Hawaii and Samoa nearly draw blood with their passionate kissing. Another point made by sceptics of the natural theory is that, if it is as natural as it is made out to be, why do different peoples react to it differently, from region to region? History records, for example, that when Westerners first came to Asia, the Japanese and Chinese considered kissing as animalistic, something as best carried out as part of love making and done only in the dark. One final, rather convincing, point in support of the theory that the kiss is a learned process rather than a natural one is the ancient Indian book of love, the Kama Sutra, which covers the art of kissing in great detail. Although they might not have been the first people to kiss, the Indians were the first to kiss-and-tell. According to an American professor of anthropology, the first written record of a couple pressing their lips together was made in India some 4,000 years ago. ''From there it must have caught on, because by 500 BC there were 200 passages written about the kiss in the Karma Sutra, '' said Professor Yaughn Bryant of Texas A & M University. ''So it seems that in 1,500 years they really got carried away by it all.'' However, Professor Bryant may only be expressing the male point of view. According to surveys conducted by females, most women wished their partners would kiss better and more often. Hundreds of American women interviewed in the famous Hite Report, written by Shere Hite, complained that their lovers seldom kiss often enough or with much feeling. A survey conducted in Japan last year by the romantic fiction publisher Harlequin reached the same conclusion. When asked to rate their current partner's kissing ability, a whopping 89 per cent of the women between the ages of 20 and 40 surveyed thought that their partners should kiss them more often and with more skill. Perhaps men should heed the advice of the feminist writer Sydney Tremayne, who said ''It does not matter that a kiss is ill-timed, if it is well placed.''