As they near the the age of twenty, or middle age, their rate of aging increases exponentially. This is considered a humane way of killing off soon-to-be unproductive workers, a necessary evil in a society perpetually starved for water supplies. However, the Freespacers reuse genetic samples to reincarnate the majority of their populace once they die. The only exceptions are those that have proven to be the least productive or undesirable, making Freespacers work harder and providing further justification for preprogrammed death.