Heritability has a very specific meaning in quantitative genetics [1], which in many ways is not what your intuition would suggest [2]. It is this usage that the article talks about that.

That said, there are plenty of critiques of this definition of heritability, and not just because it is different from what a layperson would expect it to mean.

For example, the way it is used also usually has a big problem in that the standard formula assumes that Cov(G, E) = 0 (or at least is negligible), whereas in practice that is not actually true [3, 4].

This definition of heritability is also mathematically flawed in that it assumes (without evidence) that P = G + E, or at least can be reasonably approximated this way. Given that human development is the result of a feedback loop involving genetic and environmental factors, one would expect a model closer to something like a Markov chain. Proposed justifications of a simple additive model as an approximation (e.g. via the central limit theorem for highly polygenic traits) have to my knowledge never been tested.

More recent genome-wide association studies [5] have actually shown a considerable gap between heritability estimates from genotype data and heritability estimates from twin studies, known as the "missing heritability problem".

[1] https://en.wikipedia.org/wiki/Heritability

[2] https://en.wikipedia.org/wiki/Genetic_variance

[3] https://en.wikipedia.org/wiki/Gene%E2%80%93environment_inter...

[4] https://en.wikipedia.org/wiki/Gene%E2%80%93environment_corre...

[5] https://en.wikipedia.org/wiki/Genome-wide_association_study

The heritability statistic that occurs in the literature is the ratio of genetic variance to phenotypic variance.

Two corrollaries:

* When discussing heritability results from the literature, we are discussing that statistic, not your intuitive understanding of what the word should mean.

* In the scientific literature, your conception of heritability doesn't operate. In the scientific sense, the number of hands you have has low heritability, despite being genetically determined.

I think you're going to find "let's check Wiktionary" is not the decisive move in these kinds of discussions that it is elsewhere.

I heared the same distinction as OP, but it is the other way around, it's the degree to what a trait is inherited from you parents which cannot be explained by the enviroment or Random Chance.

What you're expecting heritability to mean is essentially "are genes responsible for expressing this trait", which is very different from "can I get this trait from my parents?" which does not impose any particular method for passing on the trait.

If the study doesn't use sequenced genes of parents and children as input into the model, it can't make the distinction between genetic or non genetic influence by parents.

There is a genetic component to alcohol use disorder, for example. But if one is in an environment where there is no access to alcohol whatsoever, then that person, despite their genes, will not develop an alcohol use disorder. The disorder can still be passed from parent to child, but it's more complicated than just genes.

"Welcome to science hell, professor. This is IshKebab, he once saw something on the internet about your field of expertise and is going to spend eternity lecturing you on it."[1]

[1] https://www.tomgauld.com/shop/science-hell-print