Electronic supplementary material
Text S1. Demographic characteristics of the variables studied by sex and birth cohort. Please
note that these figures were calculated by including only those individuals for whom we had
exact age at death, i.e. censored individuals were omitted from the table.
Text S2. The number of women and men included in the analyses according to their
socioeconomic status. The difference in sample size between the sexes is because more men
than women had missing age at death or the year of last recorded appearance. Because we do
not know the actual wealth of the families, such as taxes paid or farm size, and since women
at our study period rarely had an occupation of their own, we used a husband’s occupation as
a reference to wealth and social status and to divide individuals to three wealth classes:
wealthy, middle and poor. The wealthy included noblemen, priests and free farmers, the
middle included mainly tenant farmers and craftsmen, while the poor included servants and
dependent lodgers. This categorization was based on the historical studies of Finnish
populations [1, 2].
Text S3. Table showing hazard ratios for the number of sons and daughters born by the
socioeconomic status of women and men.
Text S4. The results of Cox regression model where the number of sons and daughters born
have been replaced by the number of sons and daughters surviving to adulthood (age 15). In
these models, women’s post-reproductive survival was not related to the number of adult sons
(hazard ratio (HR) (95% CI) = 0.984 (0.940, 1.031)) or daughters (HR (95% CI) = 0.984
(0.937, 1.034)). In men, the number of adult sons (HR (95% CI) = 0.994 (0.935, 1.056)) and
daughters (HR (95% CI) = 0.948 (0.895, 1.004)) were unrelated to their post-reproductive
survival.
References
1.
Hiltunen M, Forss A, Vilkuna J 1996 Siikajokilaakson historia I. Siikajoki:
Siikajokilaakson kunnat ja seurakunnat. 907 p.
2.
Saari L, Matinolli E, Kalske M 2000 Rymättylän historia II: Luonto, 1800- ja 1900luvut, murre. Rymättylän kunta: Rymättylän seura.
Table S1. Demographic characteristics of the variables studied by sex and birth cohort.
Life-history trait
<1800
Post-reproductive lifespan (yr)
Age at last reproduction (yr)
Number of sons born
Number of adult sons
Number of daughters born
Number of adult daughters
1800-1900
Post-reproductive lifespan (yr)
Age at last reproduction (yr)
Number of sons born
Number of adult sons
Number of daughters born
Number of adult daughters
>1900
Post-reproductive lifespan (yr)
Age at last reproduction (yr)
Number of sons born
Number of adult sons
Number of daughters born
Number of adult daughters
Women
mean
std
Men
mean
std
25.43
38.04
2.69
1.65
2.53
1.64
13.70
5.77
1.99
1.38
1.87
1.38
20.07
40.07
2.48
1.56
2.43
1.60
14.07
8.09
1.99
1.34
1.96
1.39
24.69
36.78
2.58
1.61
2.43
1.56
16.31
6.49
1.90
1.52
1.80
1.47
18.75
40.11
2.71
1.66
2.56
1.58
15.14
8.43
1.94
1.55
1.93
1.52
29.60
31.97
1.65
1.39
1.42
1.25
18.92
6.25
1.38
1.29
1.24
1.19
24.90
35.41
1.66
1.44
1.50
1.29
16.16
6.70
1.43
1.30
1.45
1.40
Table S2. Number of women and men according to their socioeconomic status.
Wealthy
Middle
Poor
women
2720
4633
3813
men
1312
2579
2469
Table S3. Hazard ratios and 95% CIs for the number of sons and daughters born by women’s
and men’s socioeconomic status.
Socioeconomic status
Wealthy
Number of sons
Number of daughters
Middle
Number of sons
Number of daughters
Poor
Number of sons
Number of daughters
Women
HR (95% CI)
Men
HR (95% CI)
1.07 (1.03, 1.12)
1.02 (0.98, 1.06)
1.01 (0.96, 1.06)
0.98 (0.93, 1.02)
1.05 (1.01, 1.09)
1.04 (1.01, 1.07)
1.01 (0.96, 1.06)
1.01 (0.98, 1.04)
1.06 (1.03, 1.10)
1.02 (0.99, 1.05)
1.01 (0.96, 1.06)
1.01 (0.98, 1.03)
Table S4. Cox regression model on the association between post-reproductive survival and
the number of adult sons and daughters in Finnish women and men. In women, the influences
of age at last reproduction, socio-economic status and birth area were time-dependent (Wald
χ21 > 7.69, p < 0.056), whereas in men, the influences of age at last reproduction and birth
area were time-dependent (Wald χ21 > 6.22, p < 0.013).
Number of sons (NS)
Number of daughters (ND)
Age at last reproduction
Socio-economic status (SES)
Birth cohort
Birth area
Twinning status
NS × SES
ND × SES
df
1
1
1
2
2
4
1
2
2
Women
Wald χ2
0.44
0.40
64.5
9.95
636.7
160.3
0.89
0.26
3.74
Men
p
0.51
0.53
<0.0001
0.007
<0.0001
<0.0001
0.35
0.88
0.15
Wald χ
0.04
3.34
9.27
6.83
276.0
113.1
0.28
1.92
2
p
0.84
0.068
0.002
0.033
<0.0001
<0.0001
0.87
0.38