Race, Genes, and IQ (1995) | Hacker News Reader

Race, Genes, and IQ (1995)

bostonreview.net

22 pointshuihuiilly19 comments

It seems the key problem that incites controversy is that when geneticists say "heritability," it doesn't mean what lay-persons think it means, and sometimes, even professionals in the field get caught up in defending the wrong arguments.

To the HN crowd, here's a simple but precise definition. Heritability is the extent to which variability (e.g., the standard deviation) of a trait in one generation can be explained by the variability of that trait in the previous generation. Note that high heritability does not mean that the trait is genetically based.

Fun fact 1: since most people are raised by their parents, religion and political party affiliation are also highly heritable, but no one is suggesting that there's a genetic basis for religion or political views.

Fun fact 2: number of fingers per hand is not very heritable. Since most people who have a non-five number of fingers per hand acquired that trait non-genetically (e.g., via an accident), the variability of this trait in the population correlates very little with the variability of the trait in the previous generation.

> Fun fact 1: since most people are raised by their parents, religion and political party affiliation are also highly heritable, but no one is suggesting that there's a genetic basis for religion or political views.

Religious and political views being influenced by genetics is not only a completely valid hypothesis, but the most likely. Cultural environment is downstream of genetics, and although cultural memes look like they evolve, they're trickster replicators: subservient to genes.

> To the HN crowd, here's a simple but precise definition. Heritability is the extent to which variability (e.g., the standard deviation) of a trait in one generation can be explained by the variability of that trait in the previous generation. Note that high heritability does not mean that the trait is genetically based.

You're wrong. There are separated twin studies; they rule out stuff like "parents, religion and political party affiliation". There may in fact be some other mechanism by which heritability works, but it would have to be physical, and it would have to act in ways indistinguishable from genetics.

Also, there are plenty of people suggesting that people's religion and political views have a genetic component.

An important question here are whether we're talking about immutable genetic encoding vs genetic expression (sometimes more controversially known as "epigenetics"), which is mutable via environmental stimuli, experiences, beliefs, traumas, cultural influences, etc.

The follow-up question to that is the extent to which one's epigenetic state at birth is determined during gestation and influenced by the mother's beliefs and experiences (as well as the father's indirectly via the mother).

This would explain why some correlations are found in twin study results, but also why those correlations are never close to 100%.

It would also explain the study results that suggest inheritance of patterns like trauma/anxiety e.g., in descendants of holocaust survivors.

I'm fully aware this area is nascent and yet to be deeply researched, but hypotheses exist that are plausible and potentially explanatory of phenomena that are otherwise still unexplained.

> but no one is suggesting that there's a genetic basis for religion or political views.

Yes, they are.

They generally aren't claiming that those things are as strictly genetically determined as eye color, but there have been arguments that tendency toward certain kinds of religious and political views had significant genetic contribution.

I always like to point out that, as IQ, ZIP code is also heritable. I lived for about 49 years in the same city my mom lives.

Being a resident of Earth is also heritable.

But does it solve the diamond inheritance problem ?

How many genes have we discovered that determine your ZIP code?

Zero, that's the point ;) !

How can you prove they don't?

Har dee har. Non-whites were forbidden from moving into many zip codes by law until, IIRC, around 1958. Real estate agents kept enforcing those laws long after they were struck down, and there are still tons of properties that have "racial covenants" which forbid* the current owner selling to a non-white buyer. And such neighborhoods change their composition very slowly.

So no, the causative effect is the reverse of your implication: there are many well documented zip codes that significantly determine your genetics

* though enforcement of such clauses wouldn't stand in court today

Do you really think that there wasn't someone a century ago that made the same point ? It took a while, but here's the answer:

https://en.wikipedia.org/wiki/Twin_study

I'll let you find the outcome. It's not going to be what you want to hear: different races are different. In just about anything. That's exactly what nature is trying to achieve by having races, and therefore shouldn't come as a surprise to anyone.

I find it interesting how the post was flagged even before the discussion started.

Is it because the question of heritability of zip codes is too sensitive?

Low IQ correlates with high flag activity.

This article is from 1995.

Agreed the title should include the year of the article: 1995. It is reacting to the book "The Bell Curve" which was published in 1994. The wikipedia article is here:

https://en.wikipedia.org/wiki/The_Bell_Curve

TL;DR; White people are genetically smarter than black people.

(To be transparent: I'm a white father to a black daughter... the book is bull shit IMHO)

That said: If you enjoy genetics, I'd recommend "A Brief History of Everyone Who Ever Lived", which uses actual science and is much more recent:

https://www.goodreads.com/book/show/30135182-a-brief-history...

The author's style is entertaining and insightful, although a bit flowery. As a reviewer on Good Reads mentioned "That was very... British."

For anyone that's curious, the actual point of The Bell Curve is that modern society's knowledge economy increasingly rewards IQ, so we should be careful not to create a world that conflates "high IQ" with "good person", since you don't really get to choose your IQ. Then it goes on to try and bolster the case that picking winners based on IQ could have unforeseen negative consequences. In that setting, there is a chapter that claims that this IQ-centered culture would disadvantage certain races more than others, since there are differences between average IQ when you divide people into groups based on their race. The question of heritability arises because the authors want to argue that these differences might persist for an arbitrarily long time if they are not strictly environmental. To support this possibility, they give their interpretation of the data on this topic: that the expressed IQ differences are likely at least partially genetic.

The article OP posted argues that this is not a parsimonious explanation of what we see. The author points out that heredity and genetic determination are not synonymous, and reminds that there are a number of results that suggest environmental effects can strongly influence group IQ. Further, we cannot de-conflate the effects of passive vs. active covariance between environmental and inherited effects. An example of the these two categories is the difference between:

(Passive) "Children with high musical ability tend to be born into families that will give their child lots of music lessons"

and

(Active) "Parents tend to give their children more music lessons if they demonstrate high musical ability early in childhood"

where in both these cases an inherited trait (natural musical ability) created a double-whammy environmental effect. The former is easier to control for, but the latter requires a domain-specific hypothesis to isolate. (I'm not sure I completely followed the article here, but this is the best summary I can give.)

Thanks for the links.

At least according to the APA, there apparently is a difference in group means, though no one knows why: https://en.wikipedia.org/wiki/Intelligence:_Knowns_and_Unkno...

But, so what? This is at most a scientific curiosity. There's no rational (let alone ethical) reason to treat people differently based on the distributions of the myriad groups they happen to be a part of.

That's why we take people as we find them, as individuals, not as members of their various trait groups. Getting people to care about this is a lot more important than IQ trivia.

Reply on news.ycombinator.com