News for hackers. Stuff that matters.
Re:Scientists re-evaluating relative brain size and mammalia... by logicslave on Friday April 30, 2021 @03:13AM (#26990619)
I will just leave it at this:

For evolution to work, IQ has to be heritable, otherwise how did humans evolve intelligence? People who believe in evolution, but not in heritability of personality traits are living in a warped reality. I'm not that interested in proving my point, I'm just more shocked at how many people hold obviously false beliefs.

Re:Scientists re-evaluating relative brain size and mammalia... by AussieWog93 on Friday April 30, 2021 @03:34AM (#26990724)
It's not an "obviously false" belief, it's one backed by good data and science.

Intelligence and other personality traits are of course heritable, but controlled by thousands of genes that are unlikely to shift significantly over the course of around 50,000 years.

Intelligence and personality are also a result of culture, and we've seen a 30 point increase in IQ scores in a single century, and a similarly spectacular drop in violent crime rates.

If you honestly believe racial genetics are a significant factor, you are either willfully ignorant or unable to engage in complex thought processes yourself.

Re:Scientists re-evaluating relative brain size and mammalia... by concordDance on Friday April 30, 2021 @05:31AM (#26991396)
> Intelligence and other personality traits are of course heritable, but controlled by thousands of genes that are unlikely to shift significantly over the course of around 50,000 years.

This sounds pretty convincing, but it seems to prove too much. Doesn't this also refute the idea of individual gentic differences in intelligence? Which we know exist due to the incredibly high heritability of intelligence?

Couldn't whatever allows these differences to exist not vary in strength depending on the emvironmental pressures sustained over thousands of years?

Re:Scientists re-evaluating relative brain size and mammalia... by fighterpilot on Friday April 30, 2021 @05:07AM (#26991269)

  >  thousands of genes that are unlikely to shift significantly over the course of around 50,000 years.
Large evolutionary changes can happen rather rapidly with the right sustained pressures, certainly within a 50,000 year window.

Check out this plot of brain size over time[1]

If we can have such a dramatic increase in brain volume over a 500k year window, then we can absolutely have nontrivial changes to intelligence in a 50k year window.

  > Intelligence ... are also a result of culture
IQ differences between races may be a result of prenatal nutrition, but I struggle to believe that they're a result of culture.

The reason I doubt this is transracial adoption studies where the child is adopted out at birth to well-off white parents and tested at a very young age. So I can plausibly see how bad prenatal nutrition could have reduced this kids' IQ but attributing it to culture stretches credulity a bit, in my opinion.

(I could be wrong about that though, as the kids weren't that young, so it's plausible that there's some cultural influence from early school friends, but I still think that it strains credulity).

[1] http://aquatic-human-ancestor.org/anatomy/images/brain-size-...

Re:Scientists re-evaluating relative brain size and mammalia... by jasonwatkinspdx on Friday April 30, 2021 @11:56AM (#26995113)
Anatomically modern humans have been around for 2.5 million years. Behaviorally modern humans only about 200k. Initially this was assumed to be evidence of a simple gene that created a breakthrough to language, culture, etc. Continuing archeological evidence is now strongly slanted against that, particularly evidence from microlithic industries. It now appears far more likely that behavioral modernity emerged organically as a primitive social complex. Different locations independently discovered different pieces of the "toolkit" but it wasn't until the full kit of critical tools came together that we have the breakthrough to complex societies.

Basically, your perspective on IQ and heritability is very cartoonish. I'd suggest spending some time on wikipedia. I'd also familiarize yourself with the classic rebuttal of The Bell Curve, which clarifies the difference between heritability and genetic determinism. Culture and social complexes are heritable.

Re:Scientists re-evaluating relative brain size and mammalia... by meroes on Friday April 30, 2021 @10:49AM (#26994149)
You've done all this supposed work and don't know the difference between heritability and genetic? Someone's favorite soda is hereitable too.
Re:Scientists re-evaluating relative brain size and mammalia... by drdeca on Friday April 30, 2021 @03:34AM (#26990731)
I don’t think many people doubt that there is a substantial hereditary component to the variation in intelligence between people.

So, presumably, you are talking about something else.

There are ways of categorizing people into different groups which do not cleave reality at the joints.

The further some such categorization is from cleaving reality at the joints, the more foolish one would have to be in order to be preoccupied with an alleged connection between the categories in such a mistaken categorization, and intelligence.

Re:Scientists re-evaluating relative brain size and mammalia... by CryptoPunk on Friday April 30, 2021 @03:55AM (#26990832)
It may be necessary to acknowledge the possibility that heritable intelligence varies between demographic groups to counter accusations that society is engaging in systemic discrimination against [insert group] on the basis that disparities in achievement exist between that group and the general population.

But as it happens, rapid improvement in socioeconomic indicators were seen in the black population, which is the demographic group most commonly alleged to be a victim of systemic discrimination, BEFORE the rise of social welfare spending, and before the post-civil-rights-era racial victimhood culture (e.g. homicide rates among black Americans declined in the 40s and 50s), so the facts are actually quite supportive of the nurture side of the nurture vs nature debate on the causes of racial disparities.

Re:Scientists re-evaluating relative brain size and mammalia... by open0 on Friday April 30, 2021 @04:05AM (#26990881)
> I don’t think many people doubt that there is a substantial hereditary component to the variation in intelligence between people.

I highly doubt it. Why exactly do you think this? Because some traits have been associated with intelligence?

Re:Scientists re-evaluating relative brain size and mammalia... by drdeca on Friday April 30, 2021 @01:39PM (#26996680)
Is it not well known that smart people tend to have smart children (though there is also regression to the mean).

I’m not talking about it being correlated with other traits, just intelligence itself being heritable. Well, I say “itself”, I imagine the same genes also have other impacts on other unknown things that are not noticed, because the interactions between genes is super complicated (I think?), but that’s practically the same as “itself”.

Why else would intelligence be attractive, if it weren’t heritable?

Re:Scientists re-evaluating relative brain size and mammalia... by concordDance on Friday April 30, 2021 @05:33AM (#26991405)
Adoption and twin studies mostly. I believe the wikipedia article on heritability of intelligence is still decent enough to be a good starting point.
Re:Scientists re-evaluating relative brain size and mammalia... by open0 on Saturday May 01, 2021 @12:58AM (#27003271)
https://en.wikipedia.org/wiki/Heritability_of_IQ

This one? It does not indicate nearly the certainty that other commenters here do. Read it yourself, it's a good argument for what I'm saying. The GP characterized this scientific debate as settled, yet there is actually very slim evidence in that article for what is being claimed.

Why would it be surprising if among 1000s of the highest IQ individuals in some particular place, that there would be genetic similarities between them? It's completely possible that large groups among these people share a closer familial lineage far back into history that has influenced their present-day social and economic status, which are the factors that are actually responsible for developmental health and correspondingly intelligence, and so the genetic similarity is just a byproduct of the conferral of wealth and status between generations over a long period of time.

Re:Scientists re-evaluating relative brain size and mammalia... by concordDance on Saturday May 01, 2021 @04:46AM (#27004536)
The second paragraph in the article says heritability in our modern environment is very high, over 50%. What claim did you think was being made?

Your third paragraph makes me suspect you don't know how twin studies often work. The idea is that you measure the IQs of genetically identical twins and compare how similar they are to how similar non-identical twins are. This lets you isolate what is purely personally genetic.

Re:Scientists re-evaluating relative brain size and mammalia... by open0 on Sunday May 02, 2021 @12:22AM (#27012332)
> This lets you isolate what is purely personally genetic.

No it doesn't. Not at all actually.

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

Maybe an actual geneticist can jump in here, but it's my non-expert opinion that you all are jumping to conclusions about a topic that you're not experts in either.

Re:Scientists re-evaluating relative brain size and mammalia... by concordDance on Sunday May 02, 2021 @07:15AM (#27014169)
I am indeed not an expert in this topic. But "Not at all actually" is drastically overstating the case.

The very first critique is basically a nitpick. Yes, figures will be overestimated, but not taking into account air resistance when dropping your bowling ball off the tower of Piza isn't going to invalidate a conclusion that gravity is an accelerational force of at least 9m/s^2.

In fact, with the exception of the statistical critique by the guy with a giant axe to grind it seems mostly nitpicking. Dr Axe Grinder seems to mostly be critiquing the additive model, claiming it gives wrong results, but more recent papers (such as Polderman et al (2015)) seem to say that the additive model is mostly correct. And given the latter paper is a many-author meta-analysis rather than an emotionally charged rant by a single professor and is much more recent, I'm inclined to go with the latter paper.

Re:Scientists re-evaluating relative brain size and mammalia... by drdeca on Saturday May 01, 2021 @02:09AM (#27003698)
Why would the “what if inter-generational wealth” point impact what twin studies and such show? If the correlation between the measured IQ of monozygotic twins is substantially more than between other siblings, how would wealthy/poor ancestors impact that? Even if wealth had an impact on the probability of having twins, I still don’t see how that would result in the correlation between twins being more, even when raised apart.
Re:Scientists re-evaluating relative brain size and mammalia... by open0 on Sunday May 02, 2021 @12:19AM (#27012317)
I had other studies in mind (done in China) regarding that specific point, it's what I had assumed a lot of posters here were referring to because it's normally a favorite of people who are eager to jump to certain conclusions about genetics.

There are other problems with twin studies, most importantly that developmental health starts at conception which means that genetics are not the only thing that twins are sharing. Once again I'll refer you to Wikipedia for further criticisms of twin studies:

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

Re:Scientists re-evaluating relative brain size and mammalia... by concordDance on Sunday May 02, 2021 @07:20AM (#27014217)
The heritability estimates have also been done between biological parents, adoptive parents and their children and using comparisons between siblings and half siblings.

There have been many many papers from many angles on this over the years. The high heritability seems to be a well established fact.