Assessing gender discrimination during infancy and childhood using twins: The case of rural Spain, 1750-1950

Figures & data

Figure 1. Area of study: Middle huerva (Aragón, Spain).

Note: Dark dots refer to the localities studied here (except Zaragoza, the provincial capital) and the corresponding shaded areas to their municipal boundaries. Apart from rivers (in grey) and main roads (dotted lines), the map also depicts neighbouring villages (white dots).

Figure 2. Survival and hazard estimates of twins and singletons, 1750–1900.

Note: The left and right panel shows the survival and hazard estimates, respectively.

Source: AMHDB.

Table 1. Differences in mortality by number of living children, 1750–1900. Percentage of children who died during the first year of life by number of siblings alive and condition (twins vs. singletons)

Number of siblings alive	Twins		Single children
	Male	Female	Male	Female
0	50,6	50,9	18,3	15,9
1	46,8	47,1	17	14,3
2	40,3	42,7	16,7	14,5
3	39,8	39,7	17,2	13,9
4	31,6	39,1	15,4	14,4
5	45,8	36,8	16,4	16,2
6	25	36,7	15,2	15,2
7	33,3	10,5	16,4	15,8
8	10	11,1	15,2	13,9

Note: For the number of observations see Appendix Table A2.Source: AMHDB.

Table 2. Number of observations and sex ratios at baptism, 1750–1950

	Males	Females	Total	Sex Ratio
All twins	968	872	1,840	111.0
Same-sex twins	626	530	1,156	118.1
Mixed-sex twins	342	342	684	100.0

Source: AMHDB.

Table 3. Sex ratio of children in families giving birth to twins, 1750–1950

	1750–1799	1800–1849	1850–1899	1900–1950
Families with twins	114.6	111.4	110.9	108.3
Number of families	195	210	246	214

Source: AMHDB.

Figure 3. Survival and hazard estimates of male and female twins, 1750–1900.

Figure 4. Smoothed hazard estimates, mixed- and same-sex twins (age 0–10), 1750–1900.

Table A1 Mortality rate of twins during the first week (by day and sex), 1750–1950. Excluding Nonatos

	1	2	3	4	5	6	7
Females	1.90	2.79	3.12	1.80	2.62	2.02	2.47
	841	825	802	777	763	743	728
Males	3.21	4.11	4.52	3.61	2.97	1.33	0.81
	906	877	841	803	774	751	741
Total	2.56	3.47	3.83	2.72	2.80	1.67	1.63
	1,747	1,702	1,643	1,580	1,537	1,494	1,469

Source: AMHDB.

Table A2 Differences in mortality by number of living children, 1750–1900. Number of observations by categories (see, Table A2)

Number of siblings alive	Twins		Single children
	Male	Female	Male	Female
0	142	110	10,495	9,906
1	255	205	8,155	7,648
2	195	195	6,226	5,992
3	153	135	4,377	4,082
4	104	94	2,736	2,578
5	55	60	1,590	1,499
6	27	43	829	788
7	20	17	425	357
8	11	6	184	159

Source: AMHDB.

Table A3 Age at death of first twins (distributed in percentages) in the case of second twins surviving beyond 5 years, 1750–1950

0–6 days	7–30 days	1–5 months	6–11 months	1 year	2 years	3–4 years
23.0%	12.7%	20.6%	11.9%	17.4%	7.2%	7.2%

Note: This information is available for 126 surviving twins.Source: AMHDB.

Figure A1. Daily mortality rates during the first week, by day, sex and type of twin

Figure A2. Daily mortality rates during the first week, excluding nonatos

Figure A3. Smoothed hazard estimates, mixed- and same-sex twins (age 0–5), 1750–1950