It seems that cats and dogs that are castrated do live longer than those that don't, so lower testosterone might be correlated with longevity.
My vet explained that this is because a castrated (male) cat doesn't seek out risks, travel far, get into fights, or claim a large territory, as much as an non-castrated cat seeking to mate.
Do you know of a study that shows castrated cats live longer controlling for environmental danger, e.g. a study of indoors-only cats?
I haven't found one. While searching I found comments that castration protects against testicular cancer, enlargement of the prostrate and related infections.
On the other hand, I also found a reference stating: " two studies found that the metabolic rate of spayed and neutered cats is lower than intact cats" and that ":Spayed and neutered cats have an 8.7 times greater risk of developing diabetes than intact cats"
Leading singularity proponent Ray Kurzweil co-authored a book titled Fantastic Voyage: Live Long Enough to Live Forever. A singularity believer who thinks that if he makes it to the singularity he has an excelling chance of living forever, or at least for thousands of years, should be willing to sacrifice much for a slightly higher chance of living long enough to make it to the singularity. This is why I think singularity believers make up a vastly disproportionate percentage of members of cryonics organizations.
According to a new scientific article there is a medical procedure that might be able to greatly extend some peoples’ lives. Although we don’t have a huge amount of data one small study showed that several hundred people on average lived 14 years longer than those that didn’t get the procedure.
Singularity proponents should be extremely interested in the procedure. Indeed, a way of testing whether members of the SIAI such as Eliezer really and truly believe in the singularity is whether they at least seriously consider having the procedure.
The procedure is discussed at the end of this article.