Not to defend dishonest interpretations of science here, but… “heritability” sounds like a unfortunate choice of word for the concept described. It invites inadvertent misrepresentations.
I’m reminded of an old OB comment by Anatoly Vorobey that made the reasonable point that Kolmogorov complexity captures the human notion of “complexity” very lousily at best. (WTF, the whole universe is less complex than one planet within it?) So too it seems with “heritability”. People clearly want a number that would describe “how much the over-all level of the trait is under genetic control, and… how much the trait can change under environmental interventions”—why can’t the biologists just give them that?
Have fun trying to define what is accepted as an “environmental intervention” and what isn’t.
(Getting your head smashed in with a hammer will end up reducing your body weight rather quickly, so going by your suggestion obesity is 0% heritable.)
How about “malleability”? Obesity is malleable either way (overeating, liposuction). IQ is highly malleable downwards (hammer to head), not so much upwards (a year of schooling gives +2 points). Eye color, 0% malleable. Maybe take a derivative in effort/time/money to change a trait in the desired direction.
This will be both more useful socially and vastly easier to estimate than “heritability”, if we accept Shalizi’s proof that “heritability” is almost impossible to measure. By the way, the original post relies upon that proof.
Not to defend dishonest interpretations of science here, but… “heritability” sounds like a unfortunate choice of word for the concept described. It invites inadvertent misrepresentations.
I’m reminded of an old OB comment by Anatoly Vorobey that made the reasonable point that Kolmogorov complexity captures the human notion of “complexity” very lousily at best. (WTF, the whole universe is less complex than one planet within it?) So too it seems with “heritability”. People clearly want a number that would describe “how much the over-all level of the trait is under genetic control, and… how much the trait can change under environmental interventions”—why can’t the biologists just give them that?
Because there is no such number. More variance in the environment will mean “less heritability”.
Fix: ”...under the strongest environmental interventions known today”.
Have fun trying to define what is accepted as an “environmental intervention” and what isn’t.
(Getting your head smashed in with a hammer will end up reducing your body weight rather quickly, so going by your suggestion obesity is 0% heritable.)
How about “malleability”? Obesity is malleable either way (overeating, liposuction). IQ is highly malleable downwards (hammer to head), not so much upwards (a year of schooling gives +2 points). Eye color, 0% malleable. Maybe take a derivative in effort/time/money to change a trait in the desired direction.
This will be both more useful socially and vastly easier to estimate than “heritability”, if we accept Shalizi’s proof that “heritability” is almost impossible to measure. By the way, the original post relies upon that proof.
Let’s call it ‘genetic determinism’.
Re: WTF, the whole universe is less complex than one planet within it?
Possible, but we don’t know if that’s true or not: the Kolmogorov complexity of the universe is not known.