ABSTRACT

The evolution of mortality shows a marked deceleration at older ages. This phenomenon is generally thought to be an effect of selection: mortality decelerates because it progressively selects the most robust individuals in the cohort. Other processes, however, may contribute to mortality deceleration as well. People may not be passive in the face of ageing and may try to counter it by modifying their behaviours and lifestyles. In this paper, I propose a method to test whether selection is to be considered the unique mechanism responsible for mortality deceleration. I applied this method to the life tables of selected female cohorts drawn from the Human Mortality Database. The results indicate mortality decelerates more rapidly than predicted by the selection theory.

摘要

死亡率的演变表明，老年人年龄明显下降。通常认为这种现象是选择的结果：死亡率降低，因为它逐渐选择了同类人群中最有能力的个体。但是，其他过程也可能导致死亡率下降。人们可能不会面对衰老而变得被动，可能会尝试通过改变其行为和生活方式来应对。在本文中，我提出了一种方法来测试选择是否被认为是造成死亡率下降的唯一机制。我将此方法应用于从“人类死亡率”数据库中选出的某些女性人群的生命表中。结果表明死亡率下降的速度比选择理论所预测的要快。