Heritability — Overview:

it is incorrect to say that since the heritability of personality traits is about .6, that means that 60% of your personality is inherited from your parents and 40% comes from the environment.

Héritabilité:

L'héritabilité ne doit pas être confondue avec l'hérédité, qui est une notion différente.

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L'héritabilité ne s'applique qu'au sein d'un groupe donné dans un environnement donné, contrairement à l'hérédité qui dépend uniquement du caractère mesuré.

oui, il y a des belles phrases qui puent dans cet article... " Ce n'est pas parce qu'il y a des livres dans les bibliothèques des bourgeois que leurs enfants sont de bons lecteurs, c'est parce qu'ils ont reçu un bon patrimoine génétique. " non mais franchement!
Pour finir sur une conclusion quand même assez douteuse en plus en passant de " l'école et l'environnement culturel et scolaire n'ont qu'un rôle marginal. " à "trouver des méthodes éducatives qui contrebalancent les inégalités neurogénétiques".

I can't read French well enough, but I saw heritability so I kinda had to respond ;) Heritability tells you how much of the variation seen in a population can be explained by genetic factors. That may be because some individuals show genetic causes for a trait while others have the same trait due to trauma and in yet others the same trait is caused by a mix of genetic predisposition and environmental factors, etcetera. It is true that you cannot say that because heritability is 60% the role of genetics for that trait in a given individual is 60% too.

(I hope I'm not saying this to someone who is more educated in the subject than I am, please excuse my rudeness if I am)

No, that's something I'm pretty new to, but I'm astonished that what you're basically saying is also quickly explained in the intro of the Wikipedia article. So clearly that's something extremely fundamental and basic for anyone in the field.

Yet this (let's say so-called) scientific journalist makes this extremely bad confusion and then seems to base most of his reasoning from this completely bogus premise…

And it reeks of class warfare. (it's not because of any social privilege that we are on top, it's just that we are genetically smarter)

@Pierre Thierry Its and understandable confusion, but given the consequences in the argument it is unforgivable, in my opinion. I study population genetics, and I've noticed maaaany people in genetics who are not educated in population genetics misunderstand or at least misrepresent the terminology of heritability. I think that's just because it's a statistical term, and people are more likely to understand terminology on the individual level compared to the population level like in statistics. But when using a term like this one should do their homework(!)

Also, heritability varies greatly between populations. Imagine height as an example. In a population that lives under good conditions, with plenty of food available, the variation seen in height between people is largely explained by genetic differences. Now imagine another population that deals with serious food shortage. In such a population the variation may be explained in part by the lack of food during critical phases of growth during development.

You cannot extrapolate heritability from one population to another, because the influence of environmental factors as well as a presence of genetic factors may differ greatly between populations. I haven't read the article since it is in French (but I will give it a go tomorrow, scientific French is actually a lot easier for me than everyday talk because it follows more technical rules) but I suspect from what I read so far, that the author made this second mistake as well.

Do you know of comprehensive examples like the one you give, with actual data?

I'd have to see whether my textbooks on the matter point me towards nice examples. Please remind me if I don't get back to you tomorrow!

I've just read the article, and read an automatic translation just to make sure I've understood things well.

I've not read the research he's referring to yet though, and as heritability is a population specific trait, I can't tell whether it is ok to use this study for broader generalisations. I'm guessing it probably isn't.

So far my first thought is: why is IQ so relevant to him? Is IQ a measure of success or happiness in life? Do we want everybody to have high IQ? Isn't it way more interesting to see whether an individual is a productive member of society? Or even more important, a content and happy person? Maybe IQ is very important, but I think he should tell us why he thinks it is a good measure of anything.

Secondly, how did the study control for confounding factors? Did they control for factor that affect some types of families more than others? Did they control for genetic factors that may influence IQ indirectly (for instance a genetic disease may limit availability of proper education due to stigmas or physical constraints). I'm not saying confounding factors are a problem in this study, I just wonder about them while reading, as the author doesn't take the time to explain any of that. Which makes the article useless if you don't know whether to trust the author's judgement.

Lastly, let's assume IQ is indeed highly heritable in the relevant population with control for confounding factors and the like. What does this really mean? Does it mean an individual's IQ is determined by genetics? No it doesn't, it's a population trait. For any given individual the reason of their IQ score being low could be entirely due to environmental factors.

The rest of it is down to ethics really. It is definitely true that we are not all blessed with the same perfect brain, and realising that can be used for good or evil....

Good night!

I agree, this is a classical example of tunnel-vision on a very narrow metric and promoting it to do way more than it actually can.