Intrapair comparisons of total life span in twins and pairs of sibs.
D000206:Actuarial Analysis; D001722:Birth Order; D005190:Family; D005260:Female; D006801:Humans; D008136:Longevity; D008297:Male; D011247:Pregnancy; D014427:Twins; D014429:Twins, Dizygotic; D014430:Twins, Monozygotic