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Averaging is a convenient fiction of neuroscience

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Re: Averaging is a convenient fiction of neuroscience

#71

Post by throw_pm23 »

_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

I've heard this argument a million times, but I am very skeptical: where would the reliable data on infant mortality in ancient times come from? (so that it would allow us to compute precise values of average lifespan). All we have from those times are a few bone samples and a few anecdotes preserved in fragments.

I'm not saying anything for or against the ~33 years claim, just that I doubt that it comes from a precise estimate of expected lifespan at birth.

Re: Averaging is a convenient fiction of neuroscience

#72

Post by achierius »

throw_pm23 wrote: post #71
_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

I've heard this argument a million times, but I am very skeptical: where would the reliable data on infant mortality in ancient times come from? (so that it would allow us to compute precise values of average lifespan). All we have from those times are a few bone samples and a few anecdotes preserved in fragments. I'm not saying anything for or against the ~33 years claim, just that I doubt that it comes from a preci…

> All we have from those times are a few bone samples and a few anecdotes preserved in fragments.

This is the bit that you're missing: antiquity is generally considered to extend all the way into the 500-600s AD, with the Roman empire dominating its center and 'late antiquity' covering the whole early period of the Byzantine empire. This means that even just in Europe we have extensive documents (e.g. in the Christian era, baptism and burial records), as well as a wealth of burial evidence from which to extrapolate lifespans. If you look into the sources for Rome you'll find Egypt in particular come up a lot, which isn't an accident: the dry climate and extensive use of papyrus means that the region preserved far more records (and bodies) than any other part of the empire.

Re: Averaging is a convenient fiction of neuroscience

#73

Post by _yb2s »

dalmo3 wrote: post #46
_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

I came to the same realisation about a decade ago, after being a "science" enthusiast growing up. As you said once you see it you can't unsee it. Most of science is just a scam. The exceptions are those fields backed up by real world engineering. All of social and most of biological sciences are worse than useless, they are outright dangerous.

I think you are overreaching with that. Science at its core is curious and open minded problem solving combined with an anti-authoritarian skepticism- you accept things once you can understand and confirm them for yourself. Ideally, it is also Bayesian- e.g. considering all of the evidence, even weak evidence like personal anecdotes, while correctly keeping track of how strong or weak each bit of evidence really is.

You have the courage to trust what you understand deeply even if other powerful authorities disagree- and take the responsibility to make sure you do actually understand deeply (the conspiracy theory crowd is missing the second bit). As a practicing academic scientist, I feel like the vast majority of my colleagues with research focused academic careers also see it this way.

Nearly everything called "science" in popular culture (including school science classes, pop science books, etc.) is actually a sort of dogmatic religion that idolizes science. One of the weirdest things for me, is coming on here and when I share the type of creative thinking that actually leads scientists to new hypotheses, I am insulted and accused of being an "idiot" or "anti-science" by mostly career programmers for whom science is a religion, and not a creative process. When they talk to a scientist, they see someone that doesn't align with their fixed dogmatic views, and label it as basically the opposite of what they are actually encountering- real science looks like "pseudoscience" to them. These people would even attack someone like Isaac Newton as an idiot for daring to discuss something new that seems "weird" and idolize, e.g. a medical doctor repeating some old official stance from an institution that has been thoroughly disproven by new research.

Re: Averaging is a convenient fiction of neuroscience

#74

Post by yberreby »

robertclaus wrote: post #17

As a computer scientist, I was blown away the first time my friend explained to me that his research focused on the timing of neuron spikes, not their magnitude. After talking about it for a while I realized that machine learning neural networks are much closer to simple early models of how neuron's work (averages and all), not how neuron's actually signal. Makes sense when you consider how the latest LLM models have…

> the latest LLM models have almost as many parameters as we have neurons

I often see this take, but the apt comparison is between parameter and synapse count, not neuron count. You should be counting hidden units rather than weights if you want to compare to neuron counts.

Re: Averaging is a convenient fiction of neuroscience

#75

Post by [deleted] »

_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

[deleted]

Re: Averaging is a convenient fiction of neuroscience

#76

Post by bell-cot »

_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

> In reality the modal life expectancy of adults (most common age of death other than 0) has been pretty stable in the 70s-80s range for most of human history- the low average was almost entirely due to infant mortality.

Until the last few-ish generations, pregnancy and childbirth have been leading causes of death for women in those in-between decades of their lives.

(And obviously War and Famine, too, for both genders.)

Re: Averaging is a convenient fiction of neuroscience

#77

Post by nosianu »

throw_pm23 wrote: post #71
_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

I've heard this argument a million times, but I am very skeptical: where would the reliable data on infant mortality in ancient times come from? (so that it would allow us to compute precise values of average lifespan). All we have from those times are a few bone samples and a few anecdotes preserved in fragments. I'm not saying anything for or against the ~33 years claim, just that I doubt that it comes from a preci…

In a Gresham College video lecture about microbial disease (if only I remembered the title...) the lecturing professor briefly mentions that in Victorian Britain life expectancy was actually "higher than today" when you exclude children and women (who had a great risk of death during pregnancy and birth).

https://www.gresham.ac.uk/watch-now/return-microbes-how-infe...

The video has a text with the words.

Look for

> So, your life expectancy at five, in England, as a male, in 1870 was slightly longer than it is now, which is an extraordinary statistic, slightly shorter then if you were a female.

1870s Britain is not "ancient", but as far as medicine is concerned much closer to that than to modern times. What medicine there was wasn't even available to most people. They were pretty good with "physical" things like broken bones by then, but anything concerning microbes probably wasn't much better than what was done a thousand years earlier.

Obviously, as you point out, we don't have statistics from ancient times, only some hints, but that is the same for people making the claim about the short average life spans (without the little detail about infant and women mortality).

There also is the question of how meaningful it is to average over vastly different sections of the population (what you did and how you lived and what you ate, access to good water, hygiene), or times of famine or war.

Some related discussion, reddit, but the heavily moderated AskHistorians subreddit: https://www.reddit.com/r/AskHistorians/comments/12o4py/what_...

There we see the lower life expectancy of early agricultural societies vs. hunter-gatherers (ignoring their high number of deaths due to violence).

I think all of this also serves to illustrate OPs point about the problem of averages :-) There's just too much important information that is lost.

Re: Averaging is a convenient fiction of neuroscience

#78

Post by _yb2s »

_yb2s wrote: post #67
llm_trw wrote: post #60

Earlier quoted context omitted.

>because it distorts the picture in a different way: the modal age being high is incompatible with the incorrect assumption people are making when seeing a low average life span- that people in ancient times basically never made it to an old age in their 70s or older. I literally proved by demonstration why having a distribution with an absolute mode in the extreme most value means that 97% of people still died young…

Neither of us are wrong per se- we are saying different things that are fully compatible with one another, but are both incomplete. However, I am using a biased model on purpose while aware of its limitations, and you seem to be confusing yours with reality, which is why mine seems “wrong” to you- because my model is specifically being used to show where yours does not fit reality. Looking at mode alone is pretty use…

I wanted to add- in general if you make a simple calculation or model of some real phenomena, such as taking the mean, median, or mode of a real set of data- and the conclusions you then draw from each are fundamentally incompatible, then you made a mistake somewhere in drawing those conclusions.

The replies to my original comment are basically mostly people making this same category of mistake and arguing which is "correct" - the average or the mode of the same distribution. Unfortunately, I chose a really bad example where people already hold strong almost religious or political opinions, rather than something generic that just illustrates the math.

Re: Averaging is a convenient fiction of neuroscience

#79

Post by _yb2s »

JumpCrisscross wrote: post #30
Spooky23 wrote: post #24

Earlier quoted context omitted.

It mostly is. The biggest gains are in childhood. Aldo consider that you’re looking at figures for England and Wales, which isn’t necessarily representative. The largest contribution to improving life expectancy is measured by reductions in child mortality. The factors that drove those improvements (infection control, improved hygienic practices, food quality, regulation of food and drug purity, medicine) benefited e…

> It mostly is. The biggest gains are in childhood. The life expectancy of a 60-year old going from 74.4 to 84, or a 70-year old from 79.1 to 85.9, is significant and meaningful. Not as much as a newborn's LE going from 41.6 to 81.1. But far from "pretty stable in the 70s-80s range for most of human history." Also, recent life-expectancy increases have come from adult morality reductions [1]. [1] https://www.ncbi.nlm…

How are "74.4 to 84" and "79.1 to 85.9" "pretty far from" the "70s-80s range"?

> adult morality reductions

LOL

Re: Averaging is a convenient fiction of neuroscience

#80

Post by _yb2s »

ants_everywhere wrote: post #51
_yb2s wrote: post #7

I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things... it contains the insidious trap of feeling/sounding "rigorous" and "quantitative" while making huge assumptions that are extremely inappropriate for most real world situations. Once I started noticing this I can't stop seeing this almost everywhere- almost every news article, scientific paper, etc.…

Yeah it's a common mistake, but this is like intro to stats stuff. It's not some big secret that if you summarize a distribution with a single number then you've lost information. > I've become increasingly convinced that the idea of averaging is one of the biggest obstacles to understanding things. I'd counter that it's easily one of the biggest assistants in understanding things. The Central Limit Theorem in partic…

> this is like intro to stats stuff

Amazing how the replies to my initial comment range from angrily calling me an idiot for saying something so obviously and egregiously wrong, to claiming it is so trivial and obvious that I should not have needed to mention it.

> The solution isn't less literacy.

Indeed, I can see how what I wrote could be taken that way, I also don't think so. The problem is combining an inadequate amount of literacy, with an almost religious belief in its absolute correctness, e.g. scientism.

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