alt Hacker News> OK, but check this out: Say I redefine “hair color” to mean “hair color except ignoring epigenetic and embryonic stuff and pretending that no one ever goes gray or dyes their hair et cetera”. Now, hair color is 100% heritable. Amazing, right?
It seems incredibly disingenuous to lump together epigentics and hair dye when talking about heritability of hair color. We all know when we talk about inheriting hair color we're talking about natural hair color.
> his paper built a mathematical model that tries to simulate how long people would live in a hypothetical world in which no one dies from any non-aging related cause, meaning no car accidents, no drug overdoses, no suicides, no murders, and no (non-age-related) infectious disease.
Which is exactly what everyone means by lifespan in this context. No one on earth is trying to figure out how much genetics contributes to the odds of being hit by a bus.
> veryone seems to be interpreting this paper as follows:
>> Aha! We thought the heritability of lifespan was 23-35%. But it turns out that it’s around 50%. Now we know!
Which is the correct interpretation. Proper elimination of confounding factors is good science. The previous estimates were low because they weren't properly measuring what we are all referring to when we talk about lifespan.
This misses half the problem, which is that there aren't many intrinsic traits people care about. Your height is as biological a thing as anything else, but it's tied to your environment in the same sense as hair color. That's the point the author is making: that's it's difficult to deconfound these things, and that when we discuss "heritability", as a statistic that appears in the literature, we've always talking about confounded measures.