Table 2.

The correlation between kinship and reproductive outcome.

All couplesCouples with all ancestors known four generations back
Birth year of female N Number of children Pearson's r (P value) Children who reproduce Pearson's r (P value) Grandchildren Pearson's r (P value) N Number of children Pearson's r (P value) Children who reproduce Pearson's r (P value) Grandchildren Pearson's r (P value)
1800-1824 8,346 0.071 (4.7×10-10) 0.054 (1.6×10-6) 0.057 (3.8×10-7) 1,401 0.130 (5.1×10-3) 0.022 (6.2×10-1) 0.022 (6.3×10-1)
1825-1849 14,050 0.085 (8.8×10-23) 0.042 (1.5×10-6) 0.037 (1.8×10-5) 4,783 0.088 (1.4×10-5) 0.027 (1.7×10-1) 0.013 (5.2×10-1)
1850-1874 15,440 0.088 (2.2×10-26) 0.053 (1.2×10-10) 0.045 (5.4×10-8) 10,568 0.097 (2.4×10-18) 0.046 (3.1×10-5) 0.037 (7.9×10-4)
1875-1899 16,150 0.080 (7.2×10-23) 0.053 (4.4×10-11) 0.047 (7.0×10-9) 13,563 0.080 (3.4×10-18) 0.049 (8.4×10-8) 0.042 (3.5×10-6)
1900-1924 23,740 0.072 (2.3×10-27) 0.067 (4.9×10-24) 0.065 (6.0×10-23) 21,022 0.076 (1.5×10-25) 0.068 (6.0×10-21) 0.067 (2.1×10-20)
1925-1949 36,733 0.056 (4.0×10-27) 0.049 (4.1×10-21) 0.047 (2.1×10-19) 31,510 0.059 (2.8×10-23) 0.051 (4.4×10-18) 0.05 (1.1×10-17)
1950-1965 36,510 0.034 (6.4×10-11) 0.020 (1.5×10-4) 0.018 (6.5×10-4) 29,836 0.034 (1.6×10-8) 0.027 (2.3×10-5) 0.025 (9.8×10-5)
All 150,969 0.063 (1.5×10-129) 0.045 (3.6×10-66) 0.042 (7.6×10-58) 112,683 0.063 (2.1×10-86) 0.046 (2.8×10-46) 0.043 (6.1×10-41)