Inquiries into Human Faculty and Its Development

by Francis Galton

(E) The possible difference in the length of an urban and rural generation must not be forgotten. We, however, have reason to believe that the correction on this ground will be insignificant, because the length of a generation is found to be constant under very different circumstances of race, and therefore we should expect it to be equally constant in the same race under different conditions; such as it is, it would probably tell against the towns.

Let us now sum up the results. The corrections are not to be applied for (D) and (E), so we have only to regard (A) × (B) × (C), that this--

2681 × 74/100 × 1539/1700 1796 77
------------------------- = ---- = --
2911 × 86/100 × 1585/1700 2334 100

In other words, the rate of supply in towns to the next adult generation is only 77 per cent., or, say, three-quarters of that in the country. This decay, if it continued constant, would lead to the result that the representatives of the townsmen would be less than half as numerous as those of the country folk after one century, and only about one fifth as numerous after two centuries, the proportions being 45/100 and 21/100 respectively.

TABLE I

Census Returns of 1000 Families of Factory Hands in Coventry, and 1000 Families of Agricultural Labourers in Warwickshire, grouped according to the Age of the Mother and the Number of Children in the Family.

Age of Mother	NUMBER OF CHILDREN INFAMILY.
	0		1		2		3		4		5		6		7		8		9
	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t	F a c t o r y .	A g r i c u l t
24-25	28	17	40	31	24	32	12	10	2		1	1
26-27	19	18	36	24	36	28	23	26	8	8
28-29	18	17	32	16	20¹	33	36	23	14	23	6	6	4	1	2
30-31	13	4	23	18	24	21	28¹	31	18	22	12	15	2	5		1		1
32-33	18	11	16	14	19	13	22¹	27	23	26	21	25	9	5		1		2
34-35	14	15	11	6	17	16	28	18	31	34	14	18	12	9	5	3		1
36-37	12	17	4	11	10	13	22	14	16	20	15	25	12	10	4	5	5	2
38-39	8	6	9	15	14	17	16	21	22	23	14	22	10	15	6	7		2	1
40	8	7	3	10	8	9	13	14	8	10	7	11	3	9	7	7	2	1
Totals
Left	96	67	258	109	116	111	171	149
Middle	42	45	16	36	56	71	29	35	142	166	90	123
Outside													52	54	24	25	7	9	1
Overall	138	112	174	145	172	182	200	184	142	166	90	123	52	54	24	25	7	9	1

[ (¹) These three cases are anomalous, the Factory being less than the Agricultural. In the instance of 20-33, the anomaly is double, because the sequence of the figures shows that neither of these can be correct; certainly not the first of them.]

Note.--It will be observed to the left of the outline (here shaded in "yellow"), that is, in the upper and left hand of the table, where the mothers are young and the children few, the factory families predominate, while the agricultural are the most numerous between the outlines (here shaded in "aqua"), , that is, especially in the middle of the table, where the mothers are less young, and the family is from four to five in number. The two are equally numerous to the right of the outlines, that is, to the right of the table, where the families are large. (The remainder are shaded "silver".)

TABLE II