Population Decline in Alien Civilizations

Population decline has to eventually happen in all alien civilizations. Sooner or later, growth in population must cease, if only for the reason that all resources have been consumed and there is no way to continue to support the existing population, much less allow it to grow. This may be many centuries after asymptotic technology has been passed, and material substitution may have provided more centuries of growth, but eventually all of these ideas are found, exploited, and the end is reached.

Population decline can happen for many reasons other than resource shortages. There could be many types of calamities, that might, for example, render part of the planet uninhabitable, such as basaltic flooding. Epidemics would not be a cause, as once medical technology reaches a certain point, infections would be easily cured and prevented from spreading. An asteroid that impacts the planet could make part of it uninhabitable for a long time following the impact.

Population decline does not have to be involuntary, as it could come from a decision made by the governance to discourage population growth, or if population is generated by industrial gestation, rather than by the means which served the population well until that time, there could simply be a decision to produce less new aliens each year that ones which died. If the population is generated, at least partially, by the original biological means, there might be a decision on the part of the population involved in that process to restrict the numbers. For example, if the alien civilization is like our insect species, and only a few individuals are genetic sources for succeeding generations, then those individuals could simply decide to cooperate in generating less individuals than currently die each year, so the population numbers would go down.

Population decline might happen before asymptotic technology has been reached. At this point in the progress of an alien civilization, many other reasons can exist for population decline. There might be factions, dividing the population in a variety of ways, regionally, by some genetic factors, in a caste system or whatever. Conflict between two factions might reduce population.

Whatever the cause, one question that can be asked, is population decline in an advanced civilization destabilizing? There might be at least two mechanisms by which destabilization could happen. One exists where the civilization has different roles for individuals, based on their age. Perhaps the first quarter of each member's life is education and physical and mental growth, the second involves some critical work tasks, the third is involved with monitoring and managing, and the fourth is leisure-oriented. If the ratios of the population in the different quarters of age is critical to the functioning of the civilization, some destabilization might conceivably occur. This does not seem to be a likely possibility as the problem could simply be solved by moving the thresholds between the four sectors of the population a bit each year to adjust it to the demographics. If the civilization had no way to do this, for example, it was composed of a species that metamorphosed at a precise age, then this mechanism might be relevant. This would only be the case if the tasks were likewise immutable, or something like working hours could not be adjusted to cope with the demographic change. It is hard to see how a civilization could be so constrained by age-related functions that it would destabilize following a decision to reduce population.

The other mechanism, or set of mechanisms, might be when the functioning of the society is dependent on the continual growth of numbers of members within the civilization. This would seem to be a very unlikely situation, except that such arrangements exist on Earth, and therefore could conceivably exist elsewhere. One process by which a society could arrange itself to be dependent on growth involves the society having a hierarchy or some gradation of worth in the society, and individual members rise in the hierarchy as they grow older, provided that there are sufficient numbers in the hierarchical levels beneath them. This is called a pyramid scheme. Could an alien society arrange itself so that there was such a hierarchy, and elevation in it was principally dependent on increasing numbers? Possibly, in the pre-asymptotic technology era.

Once technology expands beyond the hard sciences, the easiest ones to figure out and organize, into those related to social organization, psychology, and others, such schemes would be recognized as undesirable in a long-term sense, and would cease to exist. Thus, only a society in its earlier stages could fall prey to such a social arrangement. Population decline would have to appear very early in the civilization’s history in order to find an era in which such a social structure would be allowed to exist.

Another Earth scheme in which continual growth is the only way to stabilize it is referred to as the Ponzi scheme. This occurs on small scales on Earth, and can be recognized as a means of deception to allow the perpetrators of such a scheme to obtain benefits which continue as long as the membership count in the Ponzi scheme participant list increases. An entire society could be structured around such a concept if there was a division of the population into two factions, one, probably quite small, which receives benefits from the larger one based on the promise that such benefits will be returned to the larger one later on, and in larger quantities. This is impossible, except if the number of participants continues to increase, or the time of payoff is pushed out further, or the amount of required contributed benefits is increased. Sooner or later there will be an unfolding of these promises, and if a large part of an alien society was involved in it, it could destabilize it. This would be part of that alien civilization’s learning experiences in the field of economics and social organization.

Are there other mechanisms by which an alien society might decide on population reduction and find that it had inadvertently destabilized itself? Perhaps it will be necessary to monitor the deceptive devices developed here on Earth to learn of some new scheme.