The principal proposal of this essay is that codes of sexual conduct emerged in human society in order to control population. In a human society living in a restricted area, such as an island or an oasis, there was an optimum population. If numbers were too low, the division of labour would cease to operate, and individuals would have to learn extra skills in addition to those they already possessed - human idleness would fall as the benefits of society were lost. But if population rose too high, limited food resources would mean increased work to find food, and falling idleness. This could result in starvation and death.
In order to avoid both these dangers, human sexual reproduction came to be socially regulated. In times when the population was too low, reproduction was encouraged. When it was too high, reproduction was discouraged. Through effective management, human societies could maintain stable population levels.
If population rises, there are a number of ways that human societies can respond to restrict population growth:
To some degree, all of these seem to have been practised at one time or other. It was customary in some societies to expose unwanted children, and leave them to die. There is also, in many societies, a preference for sons rather than daughters. Sexual restrictions usually apply much more strongly to women than to men. Virginity in women has often been admired. Men and women were segregated in monastic institutions. Prostitution, of a highly ritual kind, has been practised in some cultures. Diverse sexual practices have almost always been common.
If population falls, there are a number of ways that human societies could respond to increase population growth, which are largely the converse of the previous list:
Sexually transmitted disease
If sexually transmitted diseases are introduced, they may rapidly decimate sexually promiscuous societies. Or rather, in a society in which some people are sexually promiscuous, and others are strictly monogamous, and others celibate, the effects of sexually transmitted disease will largely fall upon the sexually promiscuous portion of the population. If the diseases are regularly fatal, the effect of an epidemic will be to leave a sexually promiscuous society composed of monogamous couples or celibate individuals.
Sexually transmitted diseases can only take on epidemic proportions in populations which are sexually promiscuous because they spread rapidly. Where individuals maintain sexually exclusive relationships, society becomes broken up into an archipelago of islands, with disease unable to leap from one to another.
These exclusive islands may be composed of single celibate individuals, monogamous couples, and husbands with several wives, or wives with several husbands, or perhaps even groups of men and women who only practise sex exclusively within the confines of the group. Indeed, a whole tribe of people on some island may practise promiscuous sex within the tribe.
However, the larger the sexually-exclusive group, the greater the danger that it be compromised by sexual relations outside the group. Therefore celibate individuals are the least likely to acquire sexually transmitted diseases, and monogamous couples are the second least likely to acquire such diseases. And since monogamous couples are able to produce children, whereas celibate individuals do not, monogamous couples are the foundation of the defence against sexually transmitted disease. Marriage may well be an institution which emerged under the onslaught of such diseases.
The most important requirement is sexually exclusivity. Married men and women should not engage in sex outside marriage. This includes incest, and using the services of prostitutes. Such exclusivity also demands that both men and women are virgins before marriage. Such exclusivity also precludes divorce and remarriage, since a society made up of divorcing and remarrying individuals is no better than a promiscuous society at preventing the spread of sexually transmitted disease. The only ground for divorce is the threat that the infidelity of a spouse threatens the health of their partner.
Author: Chris Davis
Last edited: 1 Oct 1998