About three years ago I made some calculations for my wife and I on what our life expectancy could be expected to be (*1). I used several different methods, looking more for trends than exact details. The bottom line was that we each have an expectation of living into our mid-to-late-80s, with her life expectancy a little longer than mine. In those calculations I went back to our grandparents, but now I’d like to go back a few more generations.
With a relatively small number of ancestors at each generation, it only takes one “outlier,” say an individual who passed away at age 35, to have a significant effect on the average of individuals in that generation. However, I believe that one needs to include them anyway. On the other hand, since we are looking at individuals who lived long enough to marry and have children, we are thus also excluding the impact of those who “died young,” so the below statistics are not comparable to other studies which looked a life expectancy in past generations. In order to increase the number of individuals being considered, I’m going to take my ancestors and my wife’s ancestors together instead of separately as I did in (*1).
Parents – average life span was 85
Great*3-grandparents – 69
Great*4-grandparents – 63
I’d also like to take a look at the range of ages in each generation. The below is the number of individuals in each age-range.
20-29 – 0 0 0 2 0 0
30-39 – 0 0 3 2 3 7
40-49 – 0 0 1 2 1 6
50-59 – 0 1 3 2 6 9
60-69 – 0 2 1 3 10 8
70-79 – 0 3 6 8 10 16
80-89 – 4 2 2 9 8 7
90-99+ – 0 0 0 2 2 7
Total – 4 8 16 30 40 60
I’ve chosen to stop at this point, not because I don’t have any data, but I’ve already begun finding situations where our family tree has holes in it because I have not yet been able to fully populate all the branches (for example, I only have both birth and death dates for 60 out of 128 possible ancestors in the last column). This is especially true for those lines which have more recent immigrants and where I don’t have easy access to foreign records.
In looking at the distribution of ages, I have a couple of observations. First, there are more “early deaths”, i.e. individuals who died prior to say 60, in the older generations. And secondly, except for my parent’s generation, the distribution curve for every generation tends to peak in about the same place, namely in the 70s. So, I decided to recalculate the average ages if one removed any of the “early deaths”. The averages then, for each of these generations, were 85, 73, 75, 79, 75, and 77.
So, my conclusions, at least in looking at my and my wife’s ancestors are the following:
First, the key difference over the last 200 years is not that people are living longer, but that we have better medicine and other things that have addressed diseases and conditions that caused early deaths in the past. If you lived until the age of 60, then your life expectancy did not change that much.
Second, beginning with my parents’ generation, in addition to addressing causes of early death, we have finally made some progress in increasing the life expectancy of those who live to age 60. I don’t want to extrapolate this too far just based on the above numbers since there are only four individuals represented in the average for that generation, but the Social Security Administration has calculated that individuals who reach the age of 65 have a life expectancy in the mid-80s (*2). The data for my and my wife’s ancestors confirms this result.