50 MAN THE ANIMAL 



shape and dimensions of the Ladders of Life which the respec- 

 tive cohorts of white boy babies — that of 1930 and that of 1890 

 — may be imagined as climbing. 



The construction of the Ladders is as follows: the total length 

 (or height) of each ladder is the total sfan of life, which is 

 about the same in each case — a little over 100 years. The rungs 

 of the ladder are in each case set ten years of age apart, so that 

 the bottom rung of each is at 10 years of age, the second rung 

 at 20 years, and so on. The length of the rungs — the width or 

 spread of the ladder — is, at each rung, proportional to the 

 numbers of persons in the cohort who live long enough to get 

 a foothold on that rung. Naturally both ladders are drawn to 

 the same scale in the picture. In both cases 100,000 just-born 

 white male babies are supposed to start together climbing the 

 ladder. In the case of the 1929-31 Ladder there has been placed 

 opposite each rung a calendar year date. This is meant to suggest 

 that it will be a Ladder of Life much like the one here depicted 

 that the white American boy babies born today will climb. This 

 is not an entirely wild bit of prophecy, because past experience 

 indicates that the ladder they will ascend will almost certainly 

 actually be as good as or better than this one, because it is not 

 likely that medical and public health progress will abruptly stop 

 tonight. It is progress in these two fields in the recent past — 

 within the lives of most of us here tonight — that in large part 

 has wrought the 1929-31 Ladder of Life into the shape we 

 have seen. 



It is at once evident that the two Ladders, less than half a 

 century apart in time, are quite different in shape. The one for 

 1930 has an air of broad substantiality — a solid structure that 

 holds a lot of people. The 1890 one stands on the same base, 

 but after the lowest rung is passed it becomes a rather narrow, 

 gangling thing, with much less of an air of solid stability j re- 

 sembling strikingly the sort of ladder built for fruit picking, 

 rather than the broad and heavy firemen's ladders on which 

 human lives depend. At the fifty-year rung the 1890 Ladder of 

 Life accommodated fewer than half the persons who started 



