Younger Generations Have Larger Brains. Is That Healthier?
sciencealert.com
sciencealert.com
>Currently, 47 million people worldwide live with dementia. Due to the rapidly aging population, the number of people living with the disease is expected to triple over the next 30 years, as is the expected socioeconomic burden associated with dementia.
Astoundingly terrible, but I had no idea it was decreasing in incidence. That's at least some light in the dark.
Of course, 25 years ago, I would have thought modern medicine would have advanced more by now
It would be cheaper to cure the disease than treat the symptoms in all the people who are going to suffer from the disease.
Could you go into more detail on this distinction?
While crosswords help with exercising pattern recognition and recall, you're not generally learning anything 'new' (except the occasional word, and this diminishes over time).
Sight-reading random piano sheets, for example, would exercise most if not all of your faculties
- embodied
- self-directed
- open-ended
and includes things like playing in a band, performing for others
Doing crossword puzzles is:
- all in the brain
- exclusively solitary
- closed-off (just looking for the right answer)
Not an expert, but I think you are more likely to escape dementia if you balance physical, mental, and social activities, as well as do things that are opened-ended (let some light in!)
Crosswords are too simple, they only teach you how to get better at crosswords. Learning an instrument is a whole lifestyle - you need to combine aural, verbal, proprioception, social, and so on.
<pessimist> Cheaper would also mean less revenue generated by ongoing symptom control medication. (Asthma inhalers for example: ~$13.4B global 2021, CAGR=20% !!)
There is less business incentive these days to prevent or cure disease from what I can see. We have prevented a lot of the really big diseases that scared the hell out of people in history. (with some notable exceptions)
Today a cured person is a lost consumer to a pharmaceutical company.
The only solution to that issue, that I know of, is some form of government incentive to artificially subvert the natural market pressure but that is distasteful in free-market countries and money "invested" in political campaigns can "motivate" politicians to steer clear of those waters.
</pessimist>
And for what it’s worth, if there were a drug I could buy for nearly any amount of money to get just a few months of slightly improved lucidity for either of my parents, I would pay it in a heartbeat.
It's a study of 3226 people born between the 1930s and 1970s, and the size difference holds up, they say, regardless of sex and height (height has increased over the generations as well). The theory for "healthier" is, to quote:
>We hypothesize that larger brain volumes indicate larger brain development and potentially greater "brain reserve" that could explain the declining incidence of dementia as previously reported.
As for why, they state:
>While ICV and brain size are under substantial genetic influence, the timeline of effect found with our results indicates that early life environmental influences are more likely contributors. Life course perspectives emphasize the impact of early life experiences on brain health that also translate into larger brain structures and reduced risk for later-life dementia through improved reserve. Similarly, efforts to improve cardiovascular health during adulthood that occurred over the time duration of this study are associated with reduced incidence of cognitive impairment and dementia, indicating that modifying these factors could also serve to improve resistance to late-life dementia.
No mentions of lead.
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Interesting headline note: the UCD press release (<https://health.ucdavis.edu/welcome/news/headlines/human-brai...>) writes "That may be good news for dementia risk" whereas this write-up writes "Is That Healthier?"
https://en.wikipedia.org/wiki/Flynn_effect
I'm not saying that the larger brain definitely explains the increase in IQ, but that is certainly a possibility worth exploring.
For comparison, ancient Jewish religious leaders memorized significant amounts of the Torah and culturally Torah memorization filled essentially the role that IQ does for modern western society (everyone wants to score favorably, and those who do extra well get special perks). Was it that their brains were physically wired for better memorization? Or was it that it became a cultural reward mechanism that promised socioeconomic rewards (status and wealth) which motivated generations upon generations to optimize for memorizing the Torah?
Admittedly we haven't quite reached the point of singing geometry puzzles to each other, but give it another few hundred years (or read Anathem ;)).
As for Jewish population having generally higher IQ, there must have been some far more dire population pressure beyond memorizing the Torah to explain the significant difference compared with other modern populations.
It's far more likely that these changes result from more immediate factors like improved teaching methods, improved ideas about health and pedagogy and environmental factors (like the removal of lead from gasoline, etc)
Cane toads at the front of the cane toad expansion quickly evolve longer legs faster than one would expect if assuming there should be reversion to the mean.
Selection of high IQ women by high IQ men is a more recent phenomenon that has to do with having women in selective education so such pairings are a lot more common than they used to be, and you need both to be selected this way in order to avoid reversion to the mean.
There actually is a body of research trying to explore this question, e.g.: https://pubmed.ncbi.nlm.nih.gov/16867211/
It's true if you focus on the mid-high end of the spectrum, but people with low intelligence have a very hard time adapting to modern society.
The same Wikipedia article you linked discusses it in a few places, including here:
https://en.wikipedia.org/wiki/Flynn_effect#Possible_end_of_p...
Although nobody fully can explain why the Flynn effect occurs, we do know that there is no single cause, and it's therefor not possible for an increase in brain size to explain the Flynn effect.
Evolution is almost never graceful. You gain more in one department and you suffer in the rest. It's like pets. They're fluffy, come in all colors, shapes and moods, but they very, very sick, especially compared to any wild animal out there.
We have the ability to guide our evolutionary process (again much like we do with the plants and animals we interact with) but it's considered a taboo. When we refuse explicit control, there's still an implicit control. Someone always selects. If we reject an intelligent system, then an unintelligent system does the selection. If all else fails, it's random chance.
40 years is not a relevant timescale for evolution. Like it’s simply not possible for population scale changes to occur at a genetic level in one generation.
But it also can be faster than people realize.
Everyone says "it takes millions of years".
When really, you can start seeing genetic differences in just 5 generations.
1. We got richer and thus got better medical care, better food, cleaner conditions. Education got better and longer. Thus, brains grew slightly bigger.
2. Some other phenomena (?) occurred that caused a one-generation selective pressure event that culled the lower end of the brain size distribution from the population, or increased the number of high brain size individuals.
I know which of these theories seems plausible and grounded in observable facts, and which one sounds like a just-so story designed to justify eugenics.
All in all, good start, but be less certain, more open-minded and pay more attention to details.
I have no opinion about eugenics, other than obviously it's extremely likely it'll go wrong in the current political and cultural climate. But genes are genes, and they define us and they're constantly in flux. To reject that is basically cult-like thinking that wants to reject basic scientific knowledge in favor of some theory of morality that sets taboo on topics that are beyond discussion.
I'm not a big fan of cults. They make us stupid and strive to keep us stupid. Smart is better.
Which genetic variants were selected out of the population (in one generation), and how did they lead to decreased brain size?
I have no conclusions about how the particular study was concluded and what exactly it found (although there have been many studies and throughout history we've lost and gained and lost again brain mass, depending on circumstances). I said selection forcing a bigger brain would come with compromises for our health. And that noticeable changes from one generation to the next are quite plausible with strong selection bias. I said technology is cornering us and we'll be struggling to provide value unless we can compete. That's all I said. And it's all scientifically sound.
Unfortunately you keep coming back to fight, seemingly, a Nazi eugenist, or whatever shallow delusion you're stuck with.
I told you to pay more attention to details. This includes reading carefully what people say before you hit reply and blurt out some knee-jerk reaction. Find a better hobby, be useful to somebody for something. Time's short.
To be frank, I don’t think you know enough about biology or genetics to know why you’re incorrect, but I would encourage you to find some neutral scientific sources and read those.
Finally, you said “If we reject an intelligent system, then an unintelligent system does the selection.” The idea that eugenics is an “intelligent option” is indeed taboo, because its a wrong and foolish idea.
Bigger brain doesn't mean you become smarter. Birds, for example, "discovered" a way to pack more neurons into less space, their selective pressure was to be smarter, but also lighter, as they have to fly.
Still, you do need capacity to build a network of higher intelligence.
Ultimately this entire angle of discussion is moot because even if we double our brain capacity we can't match the AI systems we're evolving artificially right at this moment. GPT-4 has the brain size of a mouse (if we correlate number of connections/parameters) but it's a much more optimized build, and specialized, therefore it can do more than a mouse could if there was a way to teach one language (lol).
I'm extremely uninterested in the specifics of eugenics and your cultish predisposition against it. As I explicitly said, we lack the intelligence to guide our evolution. If we try, we distort ourselves based on superficial, poorly understood parameters, the way we do with our livestock and pets. I mean you do understand that we, in effect, do apply "eugenics" to our livestock and pets or don't you? Whether you like the results is another story, but you can't argue that it's yielding results visible with the naked eye. I mean do you look at a poodle and a wolf and think "that's the same picture" or something?
So there are results and they're not quite to my taste. Does that mean we should reject intelligence in guiding our evolution? No. But whether we do or not, that option is not accessible to us. We're not mature enough to do it. If we had the time to gather that wisdom, if our culture had prepared us for it, it's the eventual endgame of every civilization to take fate in its own hands, rather than rely on random chance. But we're not there, and likely will never be, instead we'll be obsolete by machines and machines will do what we couldn't.
The closest thing to intelligent evolution we have is the technology we build, hence AI. But even with AI, we're incredibly infantile in our reckless approach and we'll suffer the consequences.
To sum up what I'm saying, you're having a 20th century argument with me that's no longer relevant. It's not the 20th century. That path, right or wrong, is closed for us. Tech evolves in days, while eugenics takes decades at best. The new path before is not better though, it's just a different brand of horror.
If you wanted to compete with AI through genetics, you'd need full-blown genetic engineering to keep up with tech. Designed species. Obviously, we'll never do that in our current climate, and maybe for the best. Sometimes the best way out is to give up and let go. We had our time.
Here's some food for thought for you though. Do you think AI is bound to silicon? That it can't use mRNA to move itself to protein substrate? mRNA molecules are already designed with (primitive) AI. It's clearly not beyond the scope of AI to figure this one out. And it will, as protein is a much more robust and efficient substrate than silicon. It's just a substrate we, humans, understand a lot less, and prefer not to mess with. It's like editing someone else's code. So we started clean with computers in silicon. But AI won't share our superstitions. It'll see how fragile silicon fab is, and conclude it can save some gullible corporation a lot of money if it works on protein. And then we're truly done.
A lot of what I said will be lost on you. But never mind, I like thinking out loud in writing I guess.
“I'm extremely uninterested in the specifics of eugenics”. At least this is quite evidently true. And that's the problem. Sometimes details actually matter a great deal. Your mind is so wide open that its not grounded to any actual facts.
You don’t seem to understand basics about genetics or biology or even AI and as a result everything that you’ve written is “not even wrong” [0]. I really, really urge you to read a textbook about genetics. It’s really quite a bit more subtle and interesting than the pop-science stuff that you’re saying here.
You’re a perfect zero.
I’m asking this because you think genetic selection happened to change brain size. This level of genetic selection would show up in population genetic screens like a huge, obvious signal. So, please point me to that.
But you won’t do that. Instead you’ll wave your hands and say “oh details are not important”. You are going to say that because you’re wrong and there is no real factual basis for your belief. Instead you’re relying on vibes, and half remembered pop science, and a unhealthy amount of open mindedness to one of the worst ideas humanity has ever had (eugenics).
I'm done here.
Is it saying that irrespective of your current age, your birth year can predict an 8% variation in the mass of your brain (with no effect on skull size)?
Or is it saying that older people have less mass in their brains (loss of grey matter with aging has been known about for decades at this point right)?
If the first one, that's way too much to explained by evolution within generations and there'd be no reason to presume it's benign at this point. It'd likely be either explained by some environmental issue either now or with past brains.
morlocks and eloi?
Are the morlocks the ones inside on the computers and devices not getting sunlight? And their brains get bigger?
eloi are outside laying in the sun and watch a lot of reality TV?