Freeman J T
J Am Geriatr Soc. 1975 May;23(5):200-6. doi: 10.1111/j.1532-5415.1975.tb00185.x.
The forces of mortality are the prime determinants of longevity. Longevity is a basic consideration of gerontology and includes the life expectancy of the species, the average expectancy of survival at birth, and the average of lifespan. In the history of the study of old age, for which the modern period began about 1930, there are no reports of the average lifespan for the students of aging. A survey revealed that the average lifespan of 28 special groups (15,000 individuals) was 68 years; this included an average of 68.01 years for 394 gerontologists during the same eras. These figures are comparable because the attainment of a particular status in a profession or vocation is evidence of survival to maturity. Comparison could not be made with data for the general population whose vital statistics begin at birth. The average duration of life for men whose work in part or in whole prior to the 20th century was in gerontology falls midway between the high level of 77 years for classical Greek authors and the low level of 51 years for revolutionary statesmen, and exactly between the levels of life duration for eunuchs and physical and medical scientists.
死亡率是长寿的主要决定因素。长寿是老年学的一个基本考量因素，包括物种的预期寿命、出生时的平均生存预期以及平均寿命。在大约1930年开始的现代老年学研究历史中，没有关于老年学研究者平均寿命的报告。一项调查显示，28个特殊群体（15000人）的平均寿命为68岁；这其中包括同一时期394名老年学专家的平均寿命68.01岁。这些数据具有可比性，因为在某一职业或行业中获得特定地位证明了其存活至成熟阶段。无法与从出生开始统计生命统计数据的普通人群的数据进行比较。20世纪以前部分或全部从事老年学工作的男性的平均寿命，介于古希腊作家77岁的高水平和革命政治家51岁的低水平之间，正好处于太监以及物理和医学科学家的寿命水平之间。
