Intergenerational transmission of longevity is not affected by other familial factors: evidence from 16,905 Dutch families from Zeeland, 1812-1962

Figures & data

Figure 1. Familial factors associated with offspring survival and their demographic indicators.

Figure 2. Data and variable selection.

Table 1. Characteristics of parents and offspring in the studied sample of LINKS Zeeland.

	Father	Mothers	Sons	Daughters
Sample
N	16,905	16,905	52,367	49,210
Birth cohorts	1741-1842	1768-1844	1812-1886	1812-1885
Age at death
-available	16,905	16,905	41,748 (79.7%)	39,766 (80.8%)
-censored	-	-	04,318 (08.2%)	04,821 (09.8%)
-missing	-	-	06,301 (12.0%)	04,623 (09.4%)
Demographic indicators
Age at death*	62.6 (15.6)	62.9 (17.4)	30.0 (33.1)	32.2 (33.3)
Mode lifespan	71	72	0	0
Age at last birth*	41.1 (8.1)	37.5 (5.9)	39.8 (7.5)	36.8 (6.2)
Number of offspring*	6.6 (4.0)	6.3 (3.8)	6.5 (4.0)	6.2 (3.8)
Birth spacing*	2.1 (1.3)	2.1 (1.3)	2.2 (1.3)	2.2 (1.3)
Migrated within Zeeland	15.9%	15.9%	20.1%	20.0%
Father died before ego was 5*	-	-	6.3%	6.0%
Mother died before ego was 5*	-	-	6.2%	6.2%
Age father at birth*	-	-	34.8 (7.5)	34.8 (7.5)
Age mother at birth*	-	-	31.8 (6.0)	31.8 (6.0)
Number sibs alive at birth ego*	-	-	2.4 (2.2)	2.4 (2.2)

* Mean + standard deviation between brackets

Figure 3. Cumulative hazard (a) and survival plot (b) of the association between having a top 10% surviving parent and offspring survival between ages 5–100.

Table 2. Overview of estimated Cox models.

1. Base model	Parental longevity ($Z$), sex, birth cohort ($X$)
2. Mortality model	Parental longevity ($Z$), sex, birth cohort ($X$), infant mortality in the sibship ($A$)
3. Fertility model	Parental longevity ($Z$), sex, birth cohort ($X$), having a late-reproducing mother, descending from a small sibship, parental birth spacing, parental migration, birth order, age father at birth, age mother at birth ($A$)
4. Resource model	Parental longevity ($Z$), sex, birth cohort ($X$), highest paternal SES, number of siblings alive at birth, sex-specific birth order ($A$)
5. Full model (5–100)	Parental longevity ($Z$), sex, birth cohort ($X$)
6. Full model (0–5)	Parental longevity ($Z$), sex, birth cohort ($X$), infant mortality in the sibship, descending from a small sibship, parental birth spacing, age father at birth, age mother at birth, highest paternal SES, number of siblings alive at birth ($A$)

This table provides a summary of the different models that are tested and contains notations that correspond to the general Cox-type frailty equation.

Table 3. Association between parental longevity and offspring survival between ages 5–100.

	No top 10% surviving parent	Top 10% surviving father		Top 10% surviving mother		Both parents top 10% survivors
Noffspring	38,483	7,821		5,965		1,531
Nfamilies	11,154	2,003		1,548		370
		HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value
1. Baseline	ref.	0.83 (0.79–0.87)	<0.001	0.80 (0.76–0.85)	<0.001	0.75 (0.68–0.83)	<0.001
2. Mortality	ref.	0.83 (0.79–0.87)	<0.001	0.80 (0.76–0.85)	<0.001	0.76 (0.68–0.84)	<0.001
3. Fertility	ref.	0.83 (0.79–0.87)	<0.001	0.80 (0.76–0.85)	<0.001	0.75 (0.68–0.83)	<0.001
4. Resources	ref.	0.83 (0.79–0.87)	<0.001	0.80 (0.76–0.84)	<0.001	0.75 (0.68–0.83)	<0.001
5. Full	ref.	0.83 (0.81–0.86)	<0.001	0.80 (0.77–0.83)	<0.001	0.75 (0.71–0.81)	<0.001

HR = hazard ratio, CI = confidence interval. Confidence intervals and p-values for models 1–4 are corrected for the number of variables in the dataset.

Survival benefits of having one top 10% parent or two top 10% parents differ significantly. Survival differences between having a top 10% father or top 10% mother are not significant.

Results do not change if separate Cox regressions are run between ages 5–30, 30–50, and 50–100.

Baseline model 1 contains information on having a top 10% parent, sex, and birth cohort. Mortality model 2 includes having a top 10% parent, sex, birth cohort, and infant mortality in the sibship. Familial fertility histories model 3 includes having a top 10% parent, sex birth cohort, having a late-reproducing mother, descending from a small family, mean birth intervals, parental migration, birth order, age of the father at birth, and age of the mother at birth. Shared socioeconomic resources model 4 includes having a top 10% parent, sex, birth cohort, paternal socioeconomic status, number of siblings alive at birth of ego, and sex-specific birth order. Full model 5 contains the significant variables from models 2–4: having a top 10% parent, sex, and birth cohort.

Effects of maternal longevity on offspring survival do not change after controlling for losing a parent before age 5. See Table A5 in the appendix.

Table 4. Full model (5) of the significant associations between familial resources and offspring survival between ages 5–100.

	Noffspring	Nfamilies	HR + 95% CI	p-value
Parental longevity
No top 10% parent	45,930	14,766	ref.	ref.
Father top 10%, mother not top 10%	4,294	1,072	0.83 (0.81–0.86)	<0.001
Mother top 10%, father not top 10%	3,236	822	0.80 (0.77–0.83)	<0.001
Both parents top 10%	340	79	0.75 (0.71–0.81)	<0.001

HR = hazard ratio, CI = confidence interval. Reported HRs result from the full model (5).

Survival benefits of having one top 10% parent or two top 10% parents differ significantly. Survival differences between having a top 10% father or top 10% mother are not significant.

Results do not change if separate Cox regressions are run between ages 5–30, 30–50, and 50–100.

None of the covariates associated significantly with offspring survival between ages 5–100. Effects of maternal longevity on offspring survival do not change after controlling for losing a parent before age 5. See Table A5 in the appendix.

Figure 4. Cumulative hazard (a) and survival plot (b) of the association between having a top 10% surviving parent and offspring survival between ages 0–5.

Table 5. Association between parental longevity and offspring survival between ages 0–5.

	No top 10% surviving parent	Top 10% surviving father		Top 10% surviving mother		Both parents top 10% survivors
Noffspring	74,336	14,381		10,383		2,477
Nfamilies	12,639	2,207		1,665		394
		HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value
1. Baseline	ref.	0.92 (0.88–0.97)	<0.001	0.82 (0.77–0.88)	<0.001	0.73 (0.64–0.82)	<0.001
2. Mortality	ref.	0.92 (0.88–0.96)	<0.001	0.85 (0.81–0.90)	<0.001	0.76 (0.68–0.85)	<0.001
3. Fertility	ref.	0.92 (0.87–0.97)	<0.001	0.83 (0.78–0.88)	<0.001	0.74 (0.66–0.84)	<0.001
4. Resources	ref.	0.92 (0.87–0.97)	<0.001	0.81 (0.76–0.87)	<0.001	0.72 (0.63–0.81)	<0.001
6. Full	ref.	0.93 (0.90–0.96)	<0.001	0.85 (0.82–0.89)	<0.001	0.78 (0.72–0.84)	<0.001

HR = hazard ratio, CI = confidence interval. Confidence intervals and p-values for models 1–4 are corrected for the number of variables in the dataset.

Survival benefits of having a top 10% father, a top 10% mother, or two top 10% parents differ significantly.

Baseline model 1 contains information on having a top 10% parent, sex, and birth cohort. Mortality model 2 includes having a top 10% parent, sex, birth cohort, and infant mortality in the sibship. Familial fertility histories model 3 includes having a top 10% parent, sex birth cohort, having a late-reproducing mother, descending from a small family, mean birth intervals, parental migration, birth order, age of the father at birth, and age of the mother at birth. Shared socioeconomic resources model 4 includes having a top 10% parent, sex, birth cohort, paternal socioeconomic status, number of siblings alive at birth of ego, number of siblings alive when ego was 5, and sex-specific birth order. Full model 6 contains the significant variables from models 2–4: having a top 10% parent, sex, birth cohort, sibling infant mortality, descending from a smalls sibship, parental birth spacing, age father at birth, age mother at birth, paternal socioeconomic status, and number of siblings alive at birth.

Effects of parental longevity on offspring survival do not disappear after controlling for losing a parent before age 5. See Table A6 in the appendix.

Table 6. Full model (6) of the significant associations between familial resources and offspring survival between ages 0–5.

	Noffspring	Nfamilies	HR + 95% CI	p-value
Parental longevity
● No top 10% parent	74,336	12,639	ref.	ref.
● Father top 10%, mother not top 10%	14,381	2,207	0.93 (0.90–0.96)	<0.001
● Mother top 10%, father not top 10%	10,383	1,665	0.85 (0.82–0.89)	<0.001
● Both parents top 10%	2,477	394	0.78 (0.72–0.84)	<0.001
Infant mortality
Number of infant deaths in the sibship
● 0	34,355	8,086	ref.	ref.
● 1	28,223	4,651	1.51 (1.47–1.55)	<0.001
● 2	17,273	2,176	1.82 (1.76–1.88)	<0.001
● 3+	21,726	2,052	2.12 (2.05–2.20)	<0.001
Familial fertility histories
Number of siblings
● 1	1,886	1,886	1.73 (1.61–1.86)	<0.001
● 2	3,392	1,696	1.54 (1.46–1.63)	<0.001
● 3	4,814	1,605	1.33 (1.27–1.40)	<0.001
● 4+	91,485	11,718	ref.	ref.
Parental birth spacing
● <1.5	21,972	2,978	ref.	ref.
● 1.5–2.5	60,948	9,979	0.81 (0.79–0.84)	<0.001
● >2.5	18,657	3,948	0.71 (0.68–0.74)	<0.001
Age father at birth of ego
● <25	7,698	-	0.94 (0.89–0.99)	0.012
● 25-40	70,033	-	0.95 (0.92–0.97)	<0.001
● >40	23,846	-	ref.	ref.
Age mother at birth of ego
● <25	14,725	-	0.86 (0.82–0.91)	<0.001
● 25-40	76,526	-	0.95 (0.92–0.99)	0.005
● >40	10,326	-	ref.	ref.
Shared socioeconomic resources
Highest socioeconomic status father
● Elite	2,013	308	1.05 (0.97–1.13)	0.258
● Farmers	18,162	2,597	0.72 (0.69–0.74)	<0.001
● Middle strata	33,872	5,498	0.95 (0.93–0.98)	<0.001
● Farm laborers	15,688	2,661	0.90 (0.87–0.93)	<0.001
● Laborers	30,967	5,554	ref.	ref.
● NA	875	287	0.79 (0.70–0.89)	<0.001
Number of living siblings at birth
● 0-1	43,222	-	0.85 (0.82–0.87)	<0.001
● 2-4	41,534	-	0.95 (0.92–0.97)	<0.001
● 5+	16,821	-	ref.	ref.

HR = hazard ratio, CI = confidence interval. Reported HRs result from the full model (5) and confidence intervals and p-values are corrected for the number of variables in the dataset.

Survival benefits of having a top 10% father, a top 10% mother, or two top 10% parents differ significantly.

Effects of having a late-reproducing mother, birth order, and sex-specific birth order were not significant.

Short and long birth intervals occurred both in small and large families. Moreover, there was no interaction between sibship size and birth spacing. See Table A7 in the appendix.

Effects of maternal longevity on offspring survival do not disappear after controlling for losing a parent before age 5. See Table A6 in the appendix.

Top 10% survivors as defined by the Swedish cohort life tables.

Figure A2. Visualization of disjoint family selection.

Table A1. Separate model associations between familial resources and offspring survival between ages 5–100, full table.

	N		Mortality (2)		Fertility (3)		Resources (4)		Full model (5)
	Noffspring	Nfamilies	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value
Parental longevity
No top 10% parent	38,483	11,154	ref.	ref.	ref.	ref.	ref.	ref.	ref.	ref.
Father top 10%, mother not top 10%	7,821	2,003	0.83 (0.80–0.87)	<0.001	0.83 (0.79–0.88)	<0.001	0.83 (0.79–0.87)	<0.001	0.83 (0.81–0.86)	<0.001
Mother top 10%, father not top 10%	5,965	1,548	0.80 (0.77–0.84)	<0.001	0.80 (0.76–0.85)	<0.001	0.80 (0.76–0.84)	<0.001	0.80 (0.77–0.83)	<0.001
Both parents top 10%	1,531	370	0.76 (0.69–0.83)	<0.001	0.75 (0.68–0.83)	<0.001	0.75 (0.68–0.83)	<0.001	0.75 (0.71–0.81)	<0.001
Controls
Sex (female)	27,421	12,385	STRATA	STRATA	STRATA	STRATA	STRATA	STRATA	STRATA	STRATA
Birth cohort (per 10 years)	53,800	15,075	STRATA	STRATA	STRATA	STRATA	STRATA	STRATA	STRATA	STRATA
Infant mortality
Number of infant deaths in the sibship
0	22,619	5,287	ref.	ref.	-	-	-	-	-	-
1	15,073	2,348	1.00 (0.96–1.04)	1.000	-	-	-	-	-	-
2	7,933	1,107	1.01 (0.96–1.06)	1.000	-	-	-	-	-	-
3+	8,175	959	1.04 (0.99–1.09)	0.266	-	-	-	-	-	-
Familial fertility histories
Late-reproducing mother
45+	3,446	462	-	-	1.00 (0.93–1.07)	1.000	-	-	-	-
Number of siblings
1	978	978	-	-	1.02 (0.91–1.15)	1.000	-	-	-	-
2	1781	893	-	-	0.99 (0.91–1.08)	1.000	-	-	-	-
3	2678	913	-	-	1.04 (0.97–1.12)	1.000	-	-	-	-
4+	48363	6,917	-	-	ref.	ref.	-	-	-	-
Parental birth spacing
<1.5	9,509	1,517	-	-	ref.	ref.	-	-	-	-
1.5–2.5	32,857	5,608	-	-	0.96 (0.92–1.00)	0.116	-	-	-	-
>2.5	11,704	2,576	-	-	0.97 (0.92–1.02)	1.000	-	-	-	-
Parents migrated
Yes	10,871	1,563	-	-	0.99 (0.95–1.03)	1.000	-	-	-	-
Birth order
First	9,698	-	-	-	0.95 (0.89–1.01)	0.241	-	-	-	-
Middle	10,458	-	-	-	0.96 (0.90–1.02)	0.499	-	-	-	-
Last	7,580	-	-	-	ref.	ref.	-	-	-	-
Others	26,064	-	-	-	0.96 (0.91–1.01)	0.448	-	-	-	-
Age father at birth
<25	4,435	-	-	-	0.95 (0.89–1.02)	0.662	-	-	-	-
25-40	37,386	-	-	-	0.98 (0.94–1.03)	1.000	-	-	-	-
>40	11,979	-	-	-	ref.	ref.	-	-	-	-
Age mother at birth
<25	2515	-	-	-	1.01 (.93–1.09)	1.000	-	-	-	-
25-40	6353	-	-	-	1.02 (.95–1.08)	1.000	-	-	-	-
>40	833	-	-	-	ref.	ref.	-	-	-	-
Shared socioeconomic resources
Highest socioeconomic status father
Elite	1,018	165	-	-	-	-	0.99 (0.87–1.13)	1.000	-	-
Farmers	10,652	1,664	-	-	-	-	0.99 (0.95–1.04)	1.000	-	-
Middle strata	17,810	3,202	-	-	-	-	1.00 (0.96–1.05)	1.000	-	-
Farm laborers	8,187	1,539					0.97 (0.92–1.02)	1.000
Laborers	15,600	2,957	-	-	-	-	ref.	ref.	-	-
NA	533	174	-	-	-	-	0.97 (0.82–1.14)	1.000	-	-
Number of siblings alive at birth
0-1	23,790	-	-	-	-	-	0.96 (0.92–1.02)	0.579	-	-
2-4	21,337	-	-	-	-	-	0.98 (0.93–1.02)	1.000	-	-
5+	8,673	-			-	-	ref.	ref.
Sex-specific birth order, daughters			-	-					-	-
First daughter	8,981	-	-	-	-	-	0.99 (0.92–1.06)	1.000	-	-
Other siblings	4,063	-	-	-	-	-	1.00 (0.94–1.07)	1.000	-	-
Last daughter	40,756	-			-	-	ref.	ref.
Sex-specific birth order, sons			-	-					-	-
First son	8,214	-	-	-	-	-	0.96 (0.89–1.03)	1.000	-	-
Other siblings	4,068	-	-	-	-	-	0.96 (0.90–1.02)	0.572	-	-
Last son	41,518	-	-	-	-	-	ref.	ref.	-	-

Table A2. Separate model associations between familial resources and offspring survival between ages 0–5, full table.

	N		Mortality model (2)		Fertility model (3)		Resources model (4)		Full model (6)
	Noffspring	Nfamilies	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value
Parental longevity
No top 10% parent	74,336	12,639	ref.	ref.	ref.	ref.	ref.	ref.	ref.	ref.
Father top 10%, mother not top 10%	14,381	2,207	0.92 (0.88–0.96)	<0.001	0.92 (0.87–0.97)	<0.001	0.92 (0.87–0.97)	<0.001	0.93 (0.90–0.96)	<0.001
Mother top 10%, father not top 10%	10,383	1,665	0.85 (0.81–0.90)	<0.001	0.83 (0.78–0.88)	<0.001	0.81 (0.76–0.87)	<0.001	0.85 (0.82–0.89)	<0.001
Both parents top 10%	2,477	394	0.76 (0.68–0.85)	<0.001	0.74 (0.66–0.84)	<0.001	0.72 (0.63–0.81)	<0.001	0.78 (0.72–0.84)	<0.001
Controls
Sex (female)	49,210	-	0.83 (0.80–0.85)	<0.001	0.82 (0.80–0.85)	<0.001	0.83 (0.80–0.86)	<0.001	0.83 (0.81–0.84)	<0.001
Birth cohort (per 10 years)	101,577	16,905	1.05 (1.04–1.06)	<0.001	1.04 (1.03–1.05)	<0.001	1.03 (1.01–1.04)	<0.001	1.02 (1.01–1.03)	<0.001
Infant mortality
Number of infant deaths in the sibship
0	34,355	8,086	ref.	ref.	-	-	-	-	ref.	ref.
1	28,223	4,651	1.46 (1.40–1.52)	<0.001	-	-	-	-	1.51 (1.47–1.55)	<0.001
2	17,273	2,176	1.75 (1.67–1.84)	<0.001	-	-	-	-	1.82 (1.76–1.88)	<0.001
3+	21,726	2,052	2.09 (2.00–2.19)	<0.001	-	-	-	-	2.12 (2.05–2.20)	<0.001
Familial fertility histories
Late-reproducing mother
45+	6,215	743	-	-	0.96 (0.89–1.04)	1.000	-	-	-	-
Number of siblings
1	1,886	1,886	-	-	1.21 (1.08–1.35)	<0.001	-	-	1.73 (1.61–1.86)	<0.001
2	3,392	1,696	-	-	1.12 (1.03–1.23)	<0.001	-	-	1.54 (1.46–1.63)	<0.001
3	4,814	1,605	-	-	1.04 (0.97–1.12)	1.000	-	-	1.33 (1.27–1.40)	<0.001
4+	91,485	11,718	-	-	ref.	ref.	-	-	ref.	ref.
Parental birth spacing
<1.5	21,972	2,978	-	-	ref.	ref.	-	-	ref.	ref.
1.5–2.5	60,948	9,979	-	-	0.74 (0.71–0.77)	<0.001	-	-	0.81 (0.79–0.84)	<0.001
>2.5	18,657	3,948	-	-	0.56 (0.53–0.59)	<0.001	-	-	0.71 (0.68–0.74)	<0.001
Parents migrated
Yes	20,349	2,683	-	-	0.97 (0.93–1.02)	1.000	-	-	-	-
Birth order
First	16,901	-	-	-	0.92 (0.87–0.98)	<0.001	-	-	-	-
Middle	19,486	-	-	-	0.98 (0.93–1.03)	1.000	-	-	-	-
Last	15,010	-	-	-	ref.	ref.	-	-	-	-
Others	50,180	-	-	-	0.98 (0.93–1.02)	1.000	-	-	-	-
Age father at birth
<25	7,698	-	-	-	0.92 (0.85–0.99)	0.007	-	-	0.94 (0.89–0.99)	0.012
25-40	70,033	-	-	-	0.94 (0.90–0.97)	<0.001	-	-	0.95 (0.92–0.97)	<0.001
>40	23,846	-	-	-	ref.	ref.	-	-	ref.	ref.
Age mother at birth
<25	14,725	-	-	-	0.83 (0.77–0.89)	<0.001	-	-	0.86 (0.82–0.91)	<0.001
25-40	76,526	-	-	-	0.93 (0.88–0.98)	0.002	-	-	0.95 (0.92–0.98)	0.005
>40	10,326	-	-	-	ref.	ref.	-	-	ref.	ref.
Shared socioeconomic resources
Highest socioeconomic status father
Elite	2,013	308	-	-	-	-	1.06 (0.92–1.21)	1.000	1.05 (0.97–1.13)	0.258
Farmers	18,162	2,597	-	-	-	-	0.75 (0.71–0.80)	<0.001	0.72 (0.69–0.74)	<0.001
Middle strata	33,872	5,498	-	-	-	-	0.95 (0.91–0.99)	0.008	0.95 (0.93–0.98)	<0.001
Farm laborers	15,688	2,661	-	-	-	-	0.91 (0.86–0.97)	<0.001	0.90 (0.87–0.93)	<0.001
Laborers	30,967	5,554	-	-	-	-	ref.	ref.	ref.	ref.
NA	875	287	-	-	-	-	0.84 (0.69–1.02)	0.114	0.82 (0.72–0.92)	<0.001
Number of siblings alive at birth
0-1	43,222	-	-	-	-	-	0.75 (0.72–0.79)	<0.001	0.85 (0.82–0.87)	<0.001
2-4	41,534	-	-	-	-	-	0.86 (0.83–0.90)	<0.001	0.95 (0.92–0.97)	<0.001
5+	16,821	-	-	-	-	-	ref.	ref.	ref.	ref.
Sex-specific birth order, daughters
First daughter	14,975	-	-	-	-	-	0.95 (0.89–1.02)	0.377	-	-
Other siblings	79,054	-	-	-	-	-	1.00 (0.94–1.05)	1.000	-	-
Last daughter	7,548	-	-	-	-	-	ref.	ref.	-	-
Sex-specific birth order, sons
First son	15,258	-	-	-	-	-	0.98 (0.92–1.05)	1.000	-	-
Other siblings	77,940	-	-	-	-	-	0.98 (0.93–1.04)	1.000	-	-
Last son	8,379	-	-	-	-	-	ref.	ref.	-	-

Table A3. Separate model associations between parental longevity and offspring survival between ages 5–100, robustness checks.

	N		Mortality model (2)		Fertility model (3)		Resources model (4)		Full model (5)
	Noffspring	Nfamilies	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value
Top 5%
No top 15% parent	31,161	9,239	ref.		ref.		ref.		ref.
Father top 5%, mother not top 5%	4,294	1,072	0.79 (0.74–0.84)	<0.001	0.79 (0.74–0.84)	<0.001	0.78 (0.74–0.84)	<0.001	0.79 (0.75–0.82)	<0.001
Mother top 5%, father not top 5%	3,236	822	0.75 (0.70–0.81)	<0.001	0.75 (0.70–0.81)	<0.001	0.75 (0.70–0.80)	<0.001	0.75 (0.71–0.79)	<0.001
Both parents top 5%	340	79	0.67 (0.54–0.83)	<0.001	0.67 (0.54–0.82)	<0.001	0.67 (0.54–0.82)	<0.001	0.67 (0.58–0.77)	<0.001
Top 10%
No top 15% parent	31,161	9,239	ref.		ref.		ref.		ref.
Father top 10%, mother not top 10%	7,821	2,003	0.81 (0.76–0.86)	<0.001	0.81 (0.76–0.87)	<0.001	0.81 (0.76–0.86)	<0.001	0.81 (0.78–0.85)	<0.001
Mother top 10%, father not top 10%	5,965	1,548	0.78 (0.73–0.83)	<0.001	0.78 (0.72–0.83)	<0.001	0.78 (0.72–0.83)	<0.001	0.78 (0.74–0.81)	<0.001
Both parents top 10%	1,531	370	0.69 (0.56–0.86)	<0.001	0.69 (0.56–0.85)	<0.001	0.69 (0.56–0.85)	<0.001	0.69 (0.60–0.80)	<0.001
Top 15%
No top 15% parent	31,161	9,239	ref.		ref.		ref.		ref.
Father top 15%, mother not top 15%	11,019	2,852	0.85 (0.82–0.89)	<0.001	0.85 (0.82–0.89)	<0.001	0.85 (0.81–0.89)	<0.001	0.85 (0.83–0.88)	<0.001
Mother top 15%, father not top 15%	8,214	2,150	0.82 (0.78–0.86)	<0.001	0.82 (0.78–0.86)	<0.001	0.82 (0.78–0.86)	<0.001	0.82 (0.79–0.85)	<0.001
Both parents top 15%	3,406	834	0.74 (0.69–0.80)	<0.001	0.74 (0.69–0.80)	<0.001	0.74 (0.69–0.79)	<0.001	0.74 (0.71–0.78)	<0.001

Table A4. Separate model associations between parental longevity and offspring survival between ages 0–5, robustness checks.

	N		Mortality model (2)		Fertility model (3)		Resources model (4)		Full model (6)
	Noffspring	Nfamilies	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value	HR + 95% CI	p-value
Top 5%
No top 5% parent	87,780	14,766	ref.		ref.		ref.		ref.
Father top 5%, mother not top 5%	7,782	1,166	0.87 (0.82–0.93)	<0.001	0.88 (0.82–0.94)	<0.001	0.87 (0.81–0.94)	<0.001	0.89 (0.85–0.93)	<0.001
Mother top 5%, father not top 5%	5,473	881	0.80 (0.74–0.86)	<0.001	0.77 (0.71–0.84)	<0.001	0.75 (0.69–0.81)	<0.001	0.80 (0.76–0.84)	<0.001
Both parents top 5%	542	82	0.71 (0.56–0.91)	<0.001	0.71 (0.55–0.92)	0.002	0.67 (0.51–0.87)	<0.001	0.73 (0.62–0.86)	<0.001
Top 10%
No top 10% parent	74,336	12,639	ref.		ref.		ref.		ref.
Father top 10%, mother not top 10%	14,381	2,207	0.89 (0.84–0.95)	<0.001	0.90 (0.84–0.96)	<0.001	0.89 (0.83–0.96)	<0.001	0.91 (0.87–0.95)	<0.001
Mother top 10%, father not top 10%	10,383	1,665	0.82 (0.75–0.88)	<0.001	0.79 (0.73–0.86)	<0.001	0.77 (0.70–0.83)	<0.001	0.82 (0.77–0.86)	<0.001
Both parents top 10%	2,477	394	0.73 (0.57–0.93)	0.003	0.73 (0.57–0.95)	0.006	0.68 (0.52–0.90)	<0.001	0.74 (0.63–0.88)	<0.001
Top 15%
No top 15% parent	60,963	10,538	ref.		ref.		ref.		ref.
Father top 15%, mother not top 15%	20,388	3,155	0.91 (0.87–0.95)	<0.001	0.91 (0.87–0.95)	<0.001	0.91 (0.87–0.96)	<0.001	0.92 (0.89–0.94)	<0.001
Mother top 15%, father not top 15%	14,511	2,314	0.85 (0.81–0.89)	<0.001	0.83 (0.79–0.88)	<0.001	0.81 (0.77–0.86)	<0.001	0.85 (0.82–0.88)	<0.001
Both parents top 15%	5,715	898	0.78 (0.72–0.84)	<0.001	0.76 (0.70–0.82)	<0.001	0.75 (0.68–0.81)	<0.001	0.78 (0.74–0.82)	<0.001

Table A5. Full model (5) Association between having a top 10% parent and offspring survival for offspring who did not lose a parent before age 5, between ages 5–100.

	Sample, no selections				Both parents alive at age 5
	N		Full model (5)		N		Full model (5)
	Noffspring	Nfamilies	HR + 95% CI	p-value	Noffspring	Nfamilies	HR + 95% CI	p-value
Parental longevity
No top 5% parent	38,483	11,154	ref.	ref.	34,279	6,499	ref.	ref.
Father top 5%	7,821	2,003	0.83 (0.81–0.86)	<0.001	7,437	1,225	0.83 (0.81–0.86)	<0.001
Mother top 5%	5,965	1,548	0.80 (0.77–0.83)	<0.001	5,582	1,002	0.81 (0.78–0.84)	<0.001
Both parents top 5%	1,531	370	0.75 (0.71–0.81)	<0.001	1,531	247	0.76 (0.71–0.81)	<0.001

HR = hazard ratio, CI = confidence interval. Reported HRs result from the full model (5) and confidence intervals and p-values are corrected for the number of variables in the dataset.

Full model includes parental longevity, sex, and birth cohort.

Table A6. Full model (6) associations between having a top 10% parent and offspring survival for offspring who did not lose a parent before age 5, between ages 0–5.

	Sample, no selections				Both parents alive at age 5
	N		Full model (5)		N		Full model (5)
	Noffspring	Nfamilies	HR + 95% CI	p-value	Noffspring	Nfamilies	HR + 95% CI	p-value
Parental longevity
No top 5% parent	74,336	12,639	ref.	ref.	64,172	11,215	ref.	ref.
Father top 5%	14,381	2,207	0.93 (0.90–0.96)	<0.001	13,434	2,066	0.94 (0.91–0.97)	<0.001
Mother top 5%	10,383	1,665	0.85 (0.82–0.89)	<0.001	9,627	1,581	0.89 (0.85–0.92)	<0.001
Both parents top 5%	2,477	394	0.78 (0.72–0.84)	<0.001	2,477	394	0.82 (0.76–0.88)	<0.001

HR = hazard ratio, CI = confidence interval. Reported HRs result from the full model (5) and confidence intervals and p-values are corrected for the number of variables in the dataset.

Full model includes parental longevity, sex, birth cohort, sibling infant mortality, descending from a smalls sibship, parental birth spacing, age father at birth, age mother at birth, paternal socioeconomic status, and number of siblings alive at birth.

Table A7. Association between birth spacing and offspring survival for small (2–3) and large (9+) sibships between ages 0–5 in the full model (5).

	2-3 siblings				9+ siblings
	N		Full model (6)		N		Full model (6)
	Noffspring	Nfamilies	HR + 95% CI	p-value	Noffspring	Nfamilies	HR + 95% CI	p-value
Parental birth spacing
<1.5	1,933	798	ref.	ref.	13,694	1,087	ref.	ref.
1.5–2.5	3,000	1,202	0.87 (0.80–0.94)	<0.001	31,938	2,959	0.81 (0.79–0.83)	<0.001
>2.5	3,273	1,301	0.69 (0.64–0.75)	<0.001	1,769	191	0.72 (0.69–0.75)	<0.001

HR = hazard ratio, CI = confidence interval. Reported HRs result from the full model (5) and confidence intervals and p-values are corrected for the number of variables in the dataset.

Full model includes parental longevity, sex, birth cohort, sibling infant mortality, descending from a smalls sibship, parental birth spacing, age father at birth, age mother at birth, paternal socioeconomic status, and number of siblings alive at birth.