Blogger Dennis Mangan has proposed a somewhat-convoluted theory for why females live longer than males. He thinks it has to do with ancient polygamy.
One way to test this: Comparing sex-based differences in life-expectancy in U.S. blacks vs. U.S. whites. Black-African societies practiced polygamy, whereas Northern-Europeans never have. So, if Mangan’s theory is true, black-females should live longer relative to black-males than white-females live relative to white-males.
That may sound confusing. It should make more sense in table form.
I used CDC data to make the following table:
This seems to vindicate Mangan’s theory. Doesn’t it?
Comments and Observations:
1.) Men Die Young More Often. The “pop” explanation for why women live longer: Men are killed far more often during their prime years, in accidents of all kinds, in homicides, suicides, and so on… and that they tend to have unhealthier habits (drinking, smoking). All valid points. But the beautiful thing about the CDC data is that we can look at life-expectancies for any particular age-cohort. So, if we only count persons currently 70-years-old, that would “factor-out” higher young-male mortality. Not many septegenarians are gunned down in drive-by-shootings or die in workplace accidents. The remaining length of life for people who have already survived to 60 or 70 is probably mostly-genetic. Isn’t it?
2.) True Difference Even Greater. Two things potentially mask the true sexual-dimorphisms here: a.) The black-American genepool is 20%-European: This would reduce any “native genetic sexual dimorphism” in longevity in blacks — the “pure black” dimorphism would likely be greater (presuming Northern-European genetics to be closer to 1:1 in male:female natural life-expectancies). b.) The white genepool is not 100%-Northern-European, but contains some amount of extra-European elements (which may have polygamist backgrounds). This would boost the “sexual dimorphism” in longevity for “whites”, to some extent. Despite these two things, greater sexual-dimorphism in blacks is still evident.
3.) “I Don’t Need to Go to the Doctor.” Commenter Sabril at Mangan’s blog suggests that males are more stubborn and refuse to go to the doctor more often than women. (Hence die younger). This may be so, but unless one further proposes that black-males are far more stubborn than white-males, there remains a greater sexual-dimorphism in life-expectancy among blacks.
1.) What could explain the longevity advantage black-females have (relatively) over white-females besides differing in-born genetic proclivities towards sexual-dimorphism in this way?
2.) What could explain how this genetic difference (if that is what it is) came about?