[DanielHB]

25% of humans died before reaching 5 in 1800s US, today it is <1%. Its been at least 5 generations since this value dropped dramatically.

We have not ended up with "humans which aren't as strong, aren't as smart, aren't as well adapted to a changing environment, etc."

[qsera]

> We have not ended up with "humans which aren't as strong, aren't as smart, aren't as well adapted to a changing environment, etc."

Haven't we?

[SamoyedFurFluff]

Objectively we’ve only become smarter (IQs have increased), stronger (fitness records continue to be broken), etc. since infant mortality shrank. If you believe otherwise please provide evidence.

[oneshtein]

If continuously sample range [0..inf), then average will grow with time.

[antasvara]

Is there a reason you expect IQ to be unbounded? Feels like there are physical constraints, at which point you're sampling from a truncated normal distribution (or similar).

[qsera]

So it depends on how you want to measure it.

[amanaplanacanal]

How would you measure it?

[qsera]

I would not use individual IQs. Instead I would look at how smart/dumb the general population behaves.

[throwaway173738]

This line of reasoning leads to “some people are weak and unworthy of life because they are impure.” I don’t think rolling back our work to end infant mortality to prevent weak people from living is the right answer.

[buran77]

> This line of reasoning leads to

It doesn't "lead to". Supporting a wrong conclusion even with a valid argument is as old as time. Fans of eugenics don't need an excuse to go down that path.

Our natural and artificial environments shape us for better or worse. We're bigger and more intelligent as a direct outcome of better nutrition. But we also have far more people with deadly allergies because we're so good at managing them now.

[100ms]

Probably throwing quite the grenade here, but around 29% of pregnancies end in termination globally. Absent cultural considerations, it's questionable whether life expectancy has improved in absolute terms in modern times

[flexagoon]

Child mortality rates are rapidly dropping globally as well

https://ourworldindata.org/child-mortality

https://ourworldindata.org/children-saved-global-health

[cassepipe]

I don't think it's a grenade unless you are implicitly trying to mean it that life begins before birth, which ultimately is a definition game since it's actually quite hard to define life, hard enough that calling it "life" is a matter of personal worldview. I personally think it's quite reasonable to exclude pre-birth "deaths" from life expectancy, or event infant deaths sometimes, depending on what you are trying to measure.

In any case I didn't know this number and it's quite relevant to the discussion of how much we got rid of natural selection.

[amanaplanacanal]

For those who believe in God, she performs way more abortions than humans do.

[BiteCode_dev]

We have, we just have much, much better conditions for food, hygiene, personnal safety and medicine.

But have worse hormonal health (pmc.ncbi.nlm.nih.gov/articles/PMC7063751/), and are less fit (pmc.ncbi.nlm.nih.gov/articles/PMC4033061/). The flynn effect also seems to decline in some parts of the world: www.sciencedirect.com/science/article/abs/pii/S0160289619301679

It just doesn't compensate the immense gains tech created.

Turns out it's ok to be weaker if you don't have to worry about dying of parasites, malnutrition, cold.

Which, you could conclude, means the individual is weaker, but the species is stronger.

[Mistletoe]

I like the spirit of what you are saying but the smart part isn’t true at all. IQ peaked around the mid 1990s and as someone that lived back then that tracks.

https://www.sciencedirect.com/science/article/pii/S016028962...

Look at Fig. 3. The world seems to be experiencing a reverse Flynn effect.

[antasvara]

The abstract quite literary cautions against the way you're interpreting the data. The relevant quote:

> Notably, these gains do not uniformly translate to a rise in underlying GMA, suggesting the presence of domain-specific improvements and test characteristic changes over time. Conversely, the observed decline is primarily due to decreases in word comprehension and numerical reasoning tests, also reflecting specific abilities not attributable to changes in the latent GMA factor. Our findings further challenge the validity of claims that changes in the general factor drive the Flynn effect and its reversal. Furthermore, they caution against using these scores for longitudinal studies without accounting for changes in test characteristics.

[Mistletoe]

I don’t agree with their interpretation at all and neither do lots of other studies around the world that get the same result.

> the observed decline is primarily due to decreases in word comprehension and numerical reasoning tests

What else would this be but intelligence? Imagine if your AI didn’t know what words mean and couldn’t do math and you still tried to make the assertion that it was just as intelligent.

[antasvara]

>What else would this be but intelligence? Imagine if your AI didn’t know what words mean and couldn’t do math and you still tried to make the assertion that it was just as intelligent.

Counterpoint: If I don't teach a kid to read and then ask them to do a test that has reading as a requirement, I can say two contradictory things:

1. This kid isn't intelligent. 2. I don't know what this kid's intelligence is; I gave them a test on something they weren't taught.

What you're describing is in line with 1. That's completely fair and definitely part of what I'd consider intelligence.

This paper is making a statement more in line with 2. I've seen similar conclusions elsewhere; the theories are things like "education is less and less aligned with what IQ tests measure."

In the context of fitness, I feel like 2 is more in line with what we'd be thinking about?

[throwaway676712]

IQ is not a unit, it's a z-score. Z-scores can only be compared within the same cohort against which they are computed and given the same test. Given that the cohorts and tests keep evolving over time, it makes no sense to track IQ across large time periods.

[latexr]

The reversal of the Flynn effect is more likely explained by other factors such as the explosion of social media, endless addictive entertainment, and all the attention manipulation that comes with it. Conception didn’t change that much at a large enough scale during this short time period to explain it.

[colordrops]

We haven't created humans from scratch using genetic engineering yet, why would you think our current state has anything to do with the comment you are replying to?

[wossab]

How would you know?

[krageon]

When you make an outrageous claim the burden of proof is on the claimant. Given that there isn't a real indication of anything to the contrary, it is reasonable to assume reality is still the way it always was and humans are too.

[graemep]

Which is the outrageous claim? We normally require new medical treatments to be proved safe, rather than assume they are safe until proved dangerous.

[b112]

This feels hand wavy.

I could make the same claim of a bridge before it collapses, without realising the steel was weak, or had micro fractures.

Where's the proof? What an outlandish claim! Don't you see traffic flowing as normal?

Of course, we shouldn't drop all advancement due to worries. I do think we should study the results a bit more closely though.

[grumbelbart2]

Bridges deteriorate by default. That is a well understood process with well understood reasons, which we monitor and work against. Salt, thermal cycles, load, rust.

Humanity does not deteriorate by default. Claiming it does so through some hand-wavy pseudo-evolutionary arguments is not a strong case, and requires at least some evidence to be taken serious. How about a (equally unfounded and just for the sake of argument) reverse claim: Humanity got more intelligent, because high child mortality favored physically strong children instead of mentally strong children.

[b112]

In my example, I cited microfractures and weak steel. These are not normal "deteriorate by default" methods of bridge deterioration, and have absolutely nothing to do with proper bridge construction.

They are flaws. Flaws which should never happen, separate from normal environmental degradation.

You may debate the point, but that is irrelevant, for I am referring to abnormal issues with bridges. Flaws in construction. Taking this parallel to humanity, or any evolved species, what "forges" a strong species is constantly being tempered by their environment.

Predation. Disease. Parasites. Even lack of proper nutrition. Environmental adversity, eg exposure to heat, wind, sun, etc. Reproductive errors. Reproduction issues. Etc and so forth. We've eliminated almost all of this, which means that standard methods of evolutionary pressure are almost all removed.

Species do deteriorate by default, if they remain static. Or additionally, if they allow genetic errors (which happens every generation, yes every) to seep into the gene pool without being winnowed back out by the stresses above.

These days, we save babies which are born early. Ones which have a dozen birth defects. Ones which have 100 other issues. Adults (before breeding age) with issues. Note that I am not saying we should not do these things! Only, that there is a price. A long term price.

Now... that being said, I think this is the best part of genetic engineering. It allows us to fix issues like this in the womb, and to get rid of these sorts of errors whilst still helping the current generation live, and have good lives.

But to pretend that evolutionary pressure doesn't exist, is weird. And everything we have which is an enhancement to our survival capabilities, is evolutionarily pressure based.

So back to the start? Those microfractures and weaknesses in steel are not noticeable when the bridge is deployed, as the steel's production is actually the problem. It's years later, with bridge inspections (if done! and they should be!) that these issues are discovered.

But much like global warming, or said steel, you don't want be be performing corrective action. And you can't see it before the issue becomes apparent. People didn't notice the Earth getting warmer when they were burning coal in year 1000 or some such.

We barely see the evidence of global warming now. And it's already too late to arrest some change.

Is that what you'd prefer for humanity? Wait until genetic defects are so rampant that it is "in your face" apparent?