Thread by @sharonmoalem

Why are 95% of 'supercentenarians' (those who are 110 years of age and beyond) women?

Because biological sex.

And so, a short thread on sex and longevity.

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From the beginning of life more girls make it their first birthday almost everywhere around the world, according to the @WHO. Girls have lower rates of prematurity and fewer complications after birth.

Females don't wait long to begin to dominate when it comes to survival.

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Women are naturally resistant to cancer.

Throughout life, women not only develop less cancers in organs and tissues that they share with men, but even when they do, they're much more likely to survive them.

Note: this is the case even when we adjust for behavior.

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This is Capt. John Graunt (1620 –1674). Today he's considered the father of demography and also the first to show with mathematical certainty that women have a survival advantage over men.

This was the case even though maternal mortality rates were much higher than today.

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A few minutes ago, Kane Tanaka turned 118 years old. And in so doing she smashed another two world records, both the oldest living women and oldest living person.

Tanaka's dream has finally come true.

Here she is (center of photo) at the age of 20, on her wedding day.

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Kane Tanaka (田中カ子) was born premature on January 2nd, 1903 in a small village in Japan. She not only survived her prematurity, but also went on to outlive both her husband and son.

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So why are so many more women making it to the far end of life?

The secret to Tanaka's longevity is the 'Law of Homogameity', which stipulates that the female biological survival advantage is predicated on female mammals having the use of both of their two X chromosomes.

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This is a colorized photo of Kane Tanaka on her wedding day in 1923.

Today, she turned 118 years old and because of COVID-19 hasn’t been able to see her family. If you’d like to send her a personalized message for the occasion, her great-grandson @tanakakane0102 will deliver it.