These rules dictate where, when, with whom and in what manner we flirt.We generally obey these unofficial laws instinctively, without being conscious of doing so.
This is a very obvious example, but the more complex and subtle aspects of flirting etiquette can be confusing – and most of us have made a few embarrassing mistakes.
Research shows that men find it particularly difficult to interpret the more subtle cues in women's body-language, and tend to mistake friendliness for sexual interest.
Another problem is that in some rather Puritanical cultures, such as Britain and North America, flirting has acquired a bad name.
According to some evolutionary psychologists, flirting may even be the foundation of civilisation as we know it.
They argue that the large human brain – our superior intelligence, complex language, everything that distinguishes us from animals – is the equivalent of the peacock's tail: a courtship device evolved to attract and retain sexual partners.
Our achievements in everything from art to rocket science may be merely a side-effect of the essential ability to charm.
Like every other human activity, flirting is governed by a complex set of unwritten laws of etiquette.
Flirting is much more than just a bit of fun: it is a universal and essential aspect of human interaction.
Anthropological research shows that flirting is to be found, in some form, in all cultures and societies around the world.
Flirting is a basic instinct, part of human nature.
This is not surprising: if we did not initiate contact and express interest in members of the opposite sex, we would not progress to reproduction, and the human species would become extinct.