Season of Birth and Exceptional Longevity: Comparative Study of American Centenarians, Their Siblings, and Spouses
Table 4
Month-of-birth distributions (in percent) for the US 1900 Census population, centenarians, and their siblingsa.
Month of birth
1900 Census, 5% sample Persons born in 1880–95
Centenarians
Siblings survived to age 20
,320,328
,570
Standardized residuals
,175
Standardized residuals
January
9.11
8.60
−0.671
8.88
−0.721
February
8.43
8.79
0.491
8.69
0.847
March
9.51
7.77
−2.235
9.73
0.693
April
8.50
8.03
−0.645
8.33
−0.568
May
9.08
7.07
−2.643
7.44
−5.200
June
7.17
6.62
−0.808
6.87
−1.086
July
7.78
6.37
−2.004
7.57
−0.704
August
8.51
8.54
0.034
8.27
−0.780
September
8.38
10.32
2.653
8.80
1.375
October
8.24
10.25
2.781
8.74
1.672
November
7.36
9.24
2.739
7.80
1.567
December
7.92
8.41
0.687
8.87
3.240
aMonth-of-birth distributions for both centenarians and their siblings differ from the month-of-birth distribution for the general population (individuals enumerated in the 1900 census and born in 1880–1895); difference significant at .
