Department of Sociology, The Ohio State University, 107 Townsend Hall, 1885 Neil Avenue Mall, Columbus, OH, 43210, USA,
Demography. 2014 Aug;51(4):1295-317. doi: 10.1007/s13524-014-0306-9.
This study examines historical patterns of aging through the perspectives of cohort evolution and mortality selection, where the former emphasizes the correlation across cohorts in the age dependence of mortality rates, and the latter emphasizes cohort change in the acceleration of mortality over the life course. In the analysis of historical cohort mortality data, I find support for both perspectives. The rate of demographic aging, or the rate at which mortality accelerates past age 70, is not fixed across cohorts; rather, it is affected by the extent of mortality selection at young and late ages. This causes later cohorts to have higher rates of demographic aging than earlier cohorts. The rate of biological aging, approximating the rate of the senescence process, significantly declined between the mid- and late-nineteenth century birth cohorts and stabilized afterward. Unlike the rate of demographic aging, the rate of biological aging is not affected by mortality selection earlier in the life course but rather by cross-cohort changes in young-age mortality, which cause lower rates of biological aging in old age among later cohorts. These findings enrich theories of cohort evolution and have implications for the study of limits on the human lifespan and evolution of aging.
本研究从队列演变和死亡率选择的角度考察了衰老的历史模式，前者强调了死亡率随年龄变化在各队列之间的相关性，后者强调了队列在整个生命历程中死亡率加速的变化。在对历史队列死亡率数据的分析中，我发现这两个观点都得到了支持。人口老龄化的速度，或者说死亡率在 70 岁以后加速的速度，在各队列之间并不固定；相反，它受到年轻人和晚年死亡率选择程度的影响。这导致后来的队列比早期的队列有更高的人口老龄化速度。生物衰老的速度，近似于衰老过程的速度，在 19 世纪中到后期出生的队列之间显著下降，之后稳定下来。与人口老龄化的速度不同，生物老龄化的速度不受生命早期死亡率选择的影响，而是受年轻队列之间死亡率变化的影响，这导致后来的队列在老年时的生物老龄化速度较低。这些发现丰富了队列演变理论，对人类寿命极限和衰老进化的研究具有启示意义。
