This can clearly be seen on the sex lectures put out on a two-DVD set by the British Film Institute documenting the warnings given to the young from 1917 to the 1970s.
Whatever A Man Soweth, released in 1917, warns soldiers about the dangers of cavorting with loose women in London's West End while 1932's The Mystery of Marriage compares insect and bird mating with that of humans.
1932's The Mystery Of Marriage compares insect and bird mating with that of humans. It warns it offers 'frank' explanations
In the 1917 Canadian film, a soldier named Dick is about to be tempted when an officer warns him of the risks he runs. He is then seen touring a hospital ward where men disfigured by venereal disease are shown.
In The Mystery Of Marriage, which bills itself as a 'frank' explanation, animals, insects and plants are used to explain human attraction. There is only the vaguest hint that what humans do leads to the creation of children.
In one scene a stickleback is shown to prove he's 'a real he-man' chasing the females until they accept his attentions.
Next up is a pheasant which attracts the opposite sex with its white ruff of feathers. The film advises 'shy suitors' to make themselves feel more courageous with a new set of spring clothes.
A scene from the 1917 film Whatever A Man Soweth, which here shows a soldier being approached by a prostitute
The behaviour of plants and birds in The Mystery Of Marriage is interspersed with coy references of what happens when couples kiss by haystacks
The bird's new feathers 'make him bold enough to press his suit upon a not-at-all forthcoming lady'.
Although the film accepts that a handsome appearance 'does very much influence the feminine sex,' it concedes that there will always be female perversity in every species.
In this vein, the peacock pheasant, which is not a particularly striking bird, manages to win the attention of not one, but two females at once. We then see a woman happily stepping out with a much shorter man.
Once in the 1970s the emphasis has changed to taking contraceptives so as to avoid pregnancy.
Long-haired characters are warned that unprotected sex can lead to pregnancy and abortions.
However a chauvanistic thread is maintained and in 1973's Don't Be Like Brenda! blame falls entirely on the woman for her pregnancy.
She finds herself shunned by those around while waiting for a call from her former lover.
Katy McGahan, who producted the BFI collection, told the Independent newspaper: 'Today, with teenage pregnancy rates and reported cases of sexually-transmitted disease soaring, sex education remains high on the political agenda.
'While most people accept that formal sex education is necessary, the question over who should teach it, how it should be taught, what infomation it should impart and what moral and social values it should inform remains ever contentious.'
The Joy of Sex Education is available from the BFI.
The Mystery Of Marriage, 1932