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by zevon 243 days ago
I did not say nor mean to imply that genetics do not have anything to do with IQ or intelligence. Also, context matters - this is a thread about how to structure educational environments and about certain specifics of the military. Genetics are a factor that is going to be of limited practical use in this domain, at least as far as I can fantasize OTOH.
2 comments

> I did not say nor mean to imply that genetics do not have anything to do with IQ or intelligence.

Please explain what "Correlations between socioeconomic status and success of one's offspring in educational systems don't mean that intelligence is inherited in the genetic sense." means because it sure looks like an argument that the genetic component isn't real.

Especially because you posted that in response to someone talking about heritability in very general terms, so your comment can't be interpreted as a nitpick about which evidence goes where. And I can't think of any third interpretation.

> this is a thread about how to structure educational environments and about certain specifics of the military

The idea being presented is that it's easier to run good schools when you have smarter students with smarter parents.

So the inheritability of intelligence over a single generation is critical to the argument.

Maybe what I actually meant to express becomes more clear if I re-phrase and expand the the sentence a bit:

Correlations between socioeconomic status and success of one's offspring in educational systems does not mean that you can determine genetics as a relevant factor when thinking about how to structure education and if one is interested in the relationship between success (on whatever metric) in education and family trees.

I'm neither a geneticist nor is English my first language but I've always understood "heritability" to be a term that very much has to do with genetics and the Wikipedia link you provided implies the same. If we are talking about other factors/mechanisms that impact success in educational systems and that express themselves over generations and in family structures - sure, that's basically what I'm saying.

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(Long) edit after a cup of tea and a sandwich spent over the Wikipedia-Link you provided:

I must say, I think that's pretty readable even for me as a non-geneticist. In the context of this thread, there is a lot of interesting info about "Heritability and caveats", "Influences" and "Environmental effects". I've highlighted these quotes for myself while reading:

"Although IQ differences between individuals have been shown to have a hereditary component, it does not follow that disparities in IQ between groups have a genetic basis."

"Heritability measures the proportion of variation in a trait that can be attributed to genes, and not the proportion of a trait caused by genes."

"Contrary to popular belief, two parents of higher IQ will not necessarily produce offspring of equal or higher intelligence. Polygenic traits often appear less heritable at the extremes."

The whole section on "Implications":

"Some researchers, especially those that work in fields like developmental systems theory, have criticized the concept of heritability as misleading or meaningless. Douglas Wahlsten and Gilbert Gottlieb argue that the prevailing models of behavioral genetics are too simplistic by not accounting for gene-environment interactions. Stephen Ceci also highlights the issues with this assumption, noting that they were raised by Jane Loevinger in 1943. They assert that the idea of partitioning variance makes no sense when environments and genes interact and argue that such interaction is ubiquitous in human development. They highlight their belief that heritability analysis requires a hidden assumption they call the "separation of causes", which isn't borne out by biological reality or experimental research. Such researchers argue that the notion of heritability gives the false impression that "genes have some direct and isolated influence on traits", rather than another developmental resource that a complex system uses over the course of ontogeny."

Since this is a US-centered forum, this also seems relevant:

"In the US, individuals identifying themselves as Asian generally tend to score higher on IQ tests than Caucasians, who tend to score higher than Hispanics, who tend to score higher than African Americans. Yet, although IQ differences between individuals have been shown to have a large hereditary component, it does not follow that between-group differences in average IQ have a genetic basis. In fact, greater variation in IQ scores exists within each ethnic group than between them. The scientific consensus is that genetics does not explain average differences in IQ test performance between racial groups. Growing evidence indicates that environmental factors, not genetic ones, explain the racial IQ gap."

> Although IQ differences between individuals have been shown to have a hereditary component, it does not follow that disparities in IQ between groups have a genetic basis.

This is just about race & IQ and already cedes the genetic argument that you were refusing to believe - because the evidence is so overwhelming.

> Contrary to popular belief, two parents of higher IQ will not necessarily produce offspring of equal or higher intelligence.

Not necessarily is load-bearing here in an extremely misleading way. Two parents of higher IQ are much more likely to produce an offspring of higher IQ than median.

You’re basically just cherrypicking arguments that support your incorrect supposition when compared to a mountain of evidence on the other side.

Nobody here brought up race but you/wikipedia.

Why do you insist on saying that I "don't believe" in genetic components when I've literally said the opposite? The people who wrote the stuff on the Wikipedia site I was provided with and their (researcher-)sources seem to try to tell you and me both "hey, this is an interesting field of study but it's very complicated, many genes are involved, we are far from understanding them or being able to model them, be very careful with interpreting correlations and for (m)any practical purposes (such as thinking about how to structure educational environments), you really should consider quite a lot of things not directly related to genetics." What's so controversial about that and what overwhelming evidence does that go against?

edit: Sorry, to clarify, you are saying that "Two parents of higher IQ are much more likely to produce an offspring of higher IQ than median" because of genetics as the main determining factor?

> "hey, this is an interesting field of study but it's very complicated, many genes are involved, we are far from understanding them or being able to model them, be very careful with interpreting correlations and for (m)any practical purposes (such as thinking about how to structure educational environments), you really should consider quite a lot of things not directly related to genetics."

I'll say the same thing as you: context matters. Someone trying to say that smarter parents lead to a smarter student body doesn't need to model any genes and they don't need to care about the difference between things that are transferred genetically and things that are transferred socially.

> because of genetics as the main determining factor?

Does that matter? While the word "heritability" was used, and that term "very much has to do with genetics" as you say, that person didn't directly mention genes and didn't attribute any particular percent to genes. The original argument is the same whether genes are 80% or 20%.

Again, the person I was originally replying to called intelligence "highly heritable". That does mean a genetic argument and I replied to that and not a generic assertion that there are mechanisms in play that have influence on the expression over generations.
Absolutely agreed. I got bogged down in the genetics portion, but it is not actually a necessary component of the argument I'm trying to make - merely that kids are like parents.
you’re not arguing in good faith and now you’re motte-baileying. you said:

> Correlations between socioeconomic status and success of one's offspring in educational systems don't mean that intelligence is inherited in the genetic sense. If you're seriously arguing this, you're very close to flirting with eugenics and the like.

the obvious reading is that you do not believe in a genetic component to intelligence - and in fact say that a belief in “this” is arguing for eugenics.

> Sorry, to clarify, you are saying that "Two parents of higher IQ are much more likely to produce an offspring of higher IQ than median" because of genetics as the main determining factor?

Even if you remove all environmental factors, two smart parents are more likely to have a smart kid than the counterfactual.

My original answer was a condensed and far from comprehensive one-sentence reply to another condensed one-sentence-reply (that included the phrase "highly heritable" which is how the whole genetics argument started). Why is what you apparently perceive this original one-liner to mean so important to you? I've expanded on the points I was trying to make quite a bit. And again: The researchers who look at those things seem to be the ones telling us that the relationship between intelligence and genetics is complicated and many, many non-genetic factors are in play, no? Did I miss some big new movement on deterministic genetics in education or some such since I've sat my basic biology, psychology and sociology courses? Do you know stuff that's not on Wikipedia? Help me out here, please - and I'd politely ask you to refrain from insulting my good faith.

I'd also be - again, genuinely - interested in how you come up with that clear of a statement about smart parents and their non-externally-influenced child, how one would approach that as a research question/design and how - practically - useful this piece of data in and of itself would be when most of us are not Kaspar Hauser or any other conceptual model of a human being that exists without external interdependences.

seems like a disbelief in heritable intelligence (absurd) is drawing some to use the US military as a shining star of schooling innovation without strong evidence. so seems clearly relevant and useful in this domain to identify which interventions actually work and which are just composition fx