Summary. This paper is based on in-depth historical and sociological research (Killias, 1979) exploring the conditions under which societies forbid sexual activities between persons under a certain age, where age is the only criterion for prohibition.
The laws of ancient Rome fixed the minimum ages for marrying at 14 years for boys and 12 for girls. During the Middle Ages there was no minimum age. The minimum age was left up to nature: anybody who had attained physical maturity could mary.
Since law and morality were firmly welded together, any conduct prohibited by Christian morality could - at least in principle - be punished by the secular or clerical authorities. Lawful satisfaction of sexual needs was only possible in marriage and prostitution. Adultery, bigamy, incest, sodomy, rape and abduction were criminal. But sexual activities with children were not considered as unlawful. If a child was willingly involved in the commitment of a sexual crime, such as sodomy, the child was not seen as the victim of the adult partner, but as a participant and therefore equally punishable. The adult received, at least in principle, the same punishment he would have received for committing hi crime with another adult; he was not punished just because his partner was a minor. The child was protected exactly as an adult was protected - against being the unwilling victim of rape or indecent assault. This system persisted long after the Middle Age.
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It can be assumed that sexual activity in youth will be placed under a taboo:
The longer young people are considered to remain in this state of social immaturity, the longer their sexuality will be taboo. We can also assumethat the more firmly young people are fixed in this specific position, the easier it will be for society in cases of illegal activities to shift the blame onto the adult or older partner exclusive.
Switzerland's 25 cantons can be used as a very instructive sample to test the assumed correlation between the development of the educational system and the criminal laws which deal with sexual activities among or with young people. At the end of the nineteenth century they were extremely heterogeneous both in quality of education and in those sections of criminal law which dealt with sexual offenses. For those years at the turn of the century, the correlation is actually very high between the age of consent and the criminalization of sexual behaviour among or with adolescents on one hand , the development and quality of the school system on the other hand, the latter being generally considered as the best available indicator of the degree of segregation of juveniles from adult life. In other words, cantons with highly developed educational systems tended to also have rigid statutes concerning the sexual protection of juveniles, i.e., a high age of consent. This correlation survives when control variables are introduced, such as industrialization and the percent of Protestant population.
In pre-industrial societies, the sexual activities of youth are less suppressed that those of adults in modern societies. Sexuality is taboo in modern societies until a person has attained a certain age, usually older than in early industrial societies. In the pre-industrial societies, the responsibility for sexual relations rests upon above partners, regardless of their age. In modern societies, the older partner carries the entire burden of responsibility if the younger partner has not yet attained a specific age. Besides, the prosecution of offenders against these new, legally formulated taboos imposed upon the sexuality of children and adolescents becomes increasingly independent of initiative by the family and is increasingly a task of the authorities.
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Besides, the general availability of efficient contraceptives has weakened the traditional link of sexuality, procreation and marriage. Therefore, the exclusion of adolescents from adult life, and particularly from marriage and legitimate procreation, no longer necessarily implies the opression of all forms of sexual behavior among and with juveniles. Accordingly, we may except a general tendency to reduce the age of consent. It remains to be seen whether this hypothesis holds true. So far, no such legislative change has occured in Europe. The lowering in some countries of the age of consent for homosexuality, making it identical with that for heterosexuality, appears instead to be due to an altered opinion about homosexuality rather than to a reappraisal of youth sexuality. But it seems that cases involving sexually mature and consenting juveniles below the age of consent are more frequently dropped than twenty years ago.