Baseline pupil size related to cognitive ability in proper lighting conditions
sciencedirect.com
sciencedirect.com
I'm also still very confused on what the actual relationship is purported to be, at least based on this article. How did they determine cognitive ability here?
I'm extremely wary of claims like the title, especially this one, as it seems like something children on a playground would say and use to bully each other, and certainly I imagine that many people will use it to justify being awful to others that are perceived to be "lesser" because of the rather outrageous title of the article, the article which I still really don't get how they're even making these connections to draw such a conclusion.
A few tests, among which specific memory tests. However, the memory tests didn't correlate, they claim only "fluid intelligence" correlates (even though they've also claimed the two are correlated). Fluid intelligence was measured "with the Raven’s Advanced Progressive Matrices, letter sets, and number series."
The problem, for me, is that there is nothing to relate intelligence (fluid or otherwise) and pupil size. Without something plausible linking the two, this is just meaningless.
And of course they rely on NHST statistics and a whole raft of modeling techniques, which is enough to call the whole article in doubt.
I dare say they used very visual tasks, which may be harder for people with small pupils under less than optimal lighting conditions.
Catecholamines:
https://en.wikipedia.org/wiki/Catecholamine
They're both neurotransmitters and vasoconstrictors, but the latter effect is reversed in the pupils, so they dilate your pupils. If you're low on catecholamines then your working memory is impaired and your pupils will be smaller.
This is why amphetamine dilates your pupils and is prescribed to treat ADHD.
I firmly believe that cognitive ability is a -physical- trait that can be estimated with useful and actionable results.
I base this on the simple observation that age or disease related cognitive decline is a real and measurable thing.
If cognitive decline can be measured, then cognition can be measured.
If cognition can be measured, and cognitive decline is impactful, then the variability in cognition between people is meaningful.
These measurements of cognition variability correlate strongly with real-world tasking, strongly implying that cognition is a useful metric of capability.
I don’t see how any of this is in the least bit controversial.
I don’t see how cognitive capacity is somehow bad to measure, talk about, or select for in how and why we provide education to deliver maximum utility to the student.
How is this different from athletic capability? Some people can never be pro-level basketball players no matter how much they train.
The limiting traits in that respect are products of their genes and early development. I propose that cognitive capacity is not distinct in this regard. As in any n=10^9 sample there will be outliers, but outliers are not evidence that a strongly predictive relationship does not exist.
There is no apparent reason that cognitive capacity, which is presumably based on some kind of physical neural apparatus, is somehow intrinsically malleable and non- deterministic in kind that other physical traits are not.
To claim otherwise seems an extraordinary claim requiring extraordinary evidence, of which I am at a loss to discover.
I suspect, without any substantial evidence, that this peculiar bias against the idea of determinism in cognitive ability has to do with the perception that cognitive ability is largely indeterminable externally, and many people do things to seem highly capable when they are not.
This preening behaviour is inherently threatened by the idea that it could easily be discovered, and people are defensive of this subterfuge on their own behalf and/or the behalf of others.
But, that is just a suspicion, which I would gladly be disabused of if anyone else has a better insight as to the motive behind what seems to me to be a highly illogical bias.
I think the underlying mechanism is related to neuron activation in the brain itself because it’s possible that more visual stimulation, regardless of being involved in the task at hand, helps with cognitive functioning in some manner. There are some interesting questions remaining to explore here, like would direct neuron stimulation bypass the pupil size role.
It's an interesting concept, but I don't feel like the authors defend the hypothesis very well.
Calling Raven's Progressive Matrices, a measure of "reasoning about novel problems" when it's far from novel in psychology, and most of your test subjects are psychology students?
By the way, I think they mean that Raven's Matrices test (somehow) for an ability to reason about problems that are new to the test subject, not that the test itself is new.
Apparently being intelligent (and likely needing eye correction from all that reading) as well as tall, is no fun combination. The hard life of a multi-variate outlier in the world of average ergonomics.
Is reading actually proven to cause short sightedness? I read everything I could lay my hands on from the age of four. From age ten I read at at least two hundred pages a day until I was in my thirties. I still don't need glasses at the age of nearly sixty nine. I realize that this is only one data point but I also know a lot of people who do need glasses and most of them are not and never have been avid readers.
But I spent a large amount of time out of doors tramping the fields, especially in the summer. I still do spend at least an hour out of doors every day.
[1] https://www.npr.org/sections/health-shots/2024/05/13/1250555...
And it's not a simple one-way street - drugs of course have an effect (caffeine, for a start) - but psychological factors also come into play - someone who is more able to activate their attention in response to a task will likely show a physiological response. Your pupils will "pop" in response to both pleasant (sexually attractive person) and unpleasant (unexpected large tax bill) tasks or stimuli, but the amount by which they do so is going to vary from one pair of (background conditions, situation) to the next.
I'm just intelligent, thankyouverymuch!
Also, F** ScienceDirect: https://sci-hub.se/https://doi.org/10.1016/j.cognition.2021....
poster.pdf: https://osf.io/qhjpm
Mimicry won. As with many other metrics, once something becomes a metric it no longer accurately measures what it was intended to measure.
> Race is of course a non scientific construct.
I am aware that race is a contentious topic for USians, but I don't live in the US, so please assume good intentions and understand that I am asking to understand your viewpoint, not challenge it.
Reading about historical classifications like the One drop rule shows how laughably arbitrary it is: https://en.wikipedia.org/wiki/One-drop_rule
You're referencing extremes to argue against the concept entirely which is absurd. DNA can identify groups of people with similar clusters of genes that make up a race with high accuracy. It's tracing the lineage of you and your ancestors which isn't arbitrary, and most people are sufficiently more than a drop of a given race making the delineation quite clear.
Yes, races can mix which also mixes their features, making them difficult to singularly classify. But is it necessary to not notice that in some cases larger populations have not mixed for a while and developed a common set of features?
> some adaptations to local environment happen in their bodies
I especially like that it emphasizes our common ancestry - we are all human.
If you are discounting the idea that colour is a singular indicator of race, then yes I agree with you. But that does not mean that race, as a whole, does not exist.
Race exists as a social construct. Collections of genes concentrated in a population describe something, I called it heritage. Sometimes the social construct and the heritage correspond, sometimes not. “African” only describes a race based on superficial features, not genetic variation.
I live in east Asia among people I (white American) always thought of as members of the same race, Asian. But I have learned that the people here have different racial definitions and boundaries, more tuned to their own social constructs and ideas about heritage and history. No doubt people from the African continent have different ideas about race than I got raised with. So in that sense “race” is a social construct, because different societies have different and conflicting definitions. Which do we call correct? My American/western notion of Asian as a race, or the definitions the people of Asia use?
What is the precise unambiguous definition of "race" in any case?
With Brazil you have a country in which a small few were rumoured to be exact clones of Hitler ( https://en.wikipedia.org/wiki/The_Boys_from_Brazil_(novel) ) a greater majority who are descended from European colonizers and former African slaves and a small number who "pure" descendants from the some 2,000 different tribal groups once totalling some 7 million people prior to the 1500 CE European contact.
Indonesia is a similar construct - it's a political boundary about many many distinct ethnologies from some 17,000 islands and over a quarter billion people.
I hope not.
That wasn’t the point I meant to make. The thread I replied in started with trying to explain skin color differences to a child. I had to do that with my own kids, because kids notice that people look different. I stayed away from the concept of “race” and instead tried to explain heritage and adaptation. At first glance a child might very well think Indonesians and Brazilians belong to the same race — it would depend on what features they notice. Sadly too many adults have the same level of discrimination (in both senses).
Reading older English books many years past I've seen the claim that Scottish families could be distinguished by features, I'd accept that having recognised people as being from one family or another growing, however I doubt anyone would claim the MacThoseOnes are a different race to the McThemOnes.
I saw in this post some conflation of "Africans" and "(Australian) Aboriginals", both vey large groups with very many sub groups - it's worth a mention that of all the peoples on the planet these two are perhaps the furtherest apart on the family tree as it took a good while to walk (and boat a little) to Australia and arrive here some 70K+ years past - much of Europe is likely more closely related on the great human tree to modern Africans.
To take an empirical equivalent, imagine if someone gave you two lists of people, one of whom was "tall", and the other was "short". And you measured the tall and short people, and there were people in the "short" group who were taller than average for the "tall" group, and vice versa. Their height as compared by means and standard deviations didn't vary substantially.
At that point, your assumption should be that the labeling and grouping was wrong. So too for grouping people by skin color or many other arbitrary groupings like ethnic groups and national origin.
That being said, there are groupings of people by genetic traits and things like that do matter - the classic example being broad African-American susceptibility to certain genetic-influenced illnesses like diabetes and heart disease. These are markers that more recent African immigrants don't show, and are likely a result of strong genetic and epigenetic selection for certain kinds of robustness as a result of the historical conditions they were subject to, i.e. slavery, discrimination, and poverty.
In the last 11 Olympics, men with Sub-Saharan African ancestry have earned 87 of 88 finalist berths in the 100m dash. Is this random chance or does race correlate with some genetic traits enabling differentiation in physical abilities?
>grouping people by skin color or many other arbitrary groupings
This isn't arbitrary, when common ancestry and origin impart real world observable differences in a repeatable predictable way.
>there are groupings of people by genetic traits and things like that do matter
Yea exactly.
First, you're completely forgetting culture. Second, nobody is claiming that there is no genetic difference between humans, it's just that the races we define don't correlate very well with them. Sub-Saharan Africa has the most human genetic diversity, so why would they be all of the same race?
Notice how they all come from specific population that is a small subset of black race. Probably more black people run slower then them than there is white people in total.
If you noticed that 99 of 100 finalists of some jumping discipline were Ashkenazi Jews or western Slovenians you wouldn't claim that white race is awesome at jumping.
That's why concept of race is useless. It focuses on superficial differences and similarities ignoring the real significant ones.
That's not a race. That's a particular tiny subset of a particular region with unique genetics. It's not even "Sub-Saharan", it's specific regions and tribes in Ethiopia, Kenya, and other rift countries.
> This isn't arbitrary, when common ancestry and origin impart real world observable differences in a repeatable predictable way.
Where they do, great, but often the standard "racial types" share little if anything. Skin color dictates almost nothing about the other traits of a person, so if you're concerned with "how fast do they get a sunburn", by all means group away. If you're concerned with IQ or athletic ability, try again.
The same is true for men and women for a wide range of characteristics yet we sometimes find useful to differentiate one from the other in some contexts.
> I mean the categories that have been selected, are absolutely ridiculous. There isn't just one "black", as much as there is one "white".
Should a different eye color detemine a race demarcation? Is e.g. religion a factor in detemining a race?
The examples you listed are probably better described as ethnic groups, which are not genetically detemined, not necessarily mutually exclusive and quite vaguely defined.
Italy builds many classes of cars. We still classify them as luxury vehicles, sports vehicles, economy vehicles, etc. even if some parts are interchangable. The Lamborghini Diablo used passenger bus taillights.
If you are lumping them together into "African", then I agree that _your_ notion of race is wrong. But not the concept as a whole.
(That Proclaimers song - "... and I would walk 500 miles" - turns out to be an order-of-magnitude underestimate of how far the 99th percentile will walk to get laid - and on a timescale of centuries/millennia, it's the 99th percentile that matters).
And remember that in the US (and, for example, South Africa), that social construct extended to become a _legal_ construct used to discriminate against those designated as black. Most of Europe doesn't share that unhappy recent history (although we have our own, of course), it's hard to appreciate just how much more contentious it is in the US than Europe.
From an also non-USian.
There's probably a whole Venn diagram or tree to describe different races, how far up the tree we go to describe someone pretty much depends on how far away we are from them on that tree. And then there are people of mixed race - we are all human after all.
For a non scientific concept it's surprising very highly predictive. Somehow, when I was living in Japan, every Japanese could guess I was a foreigner without me saying anything! For some strange reason that also happened to my Nigerian friend. I wish science could investigate this phenomenon and give it a name...
In a homogenous population like Japanese the distinction seems trivial to observe. In Europe or the USA, with more heterogenous populations “foreigners” get harder to identify, and race gets based on superficial features rather than heritage. More than one stupid American politician has called out Spanish or Chinese speakers as foreigners even though their ancestors go as far back in the US as most caucasians.
I once worked with a Nigerian woman who bristled and complained when our HR manager referred to her as “African American,” the politically correct term. Yetunde insisted on Nigerian, wanting no association with African Americans. Not the same race to her. That people around the world have very different definitions and boundaries when it comes to “race” tells you that it’s a social construct.
[Before someone corrects me, I know Japanese doesn’t really describe a homogenous population or ancestry from a handful of ancient ancestors. Japanese only seem homogenous relative to the US and Europe. I live in east Asia among people who don’t see other “Asians” as members of the same race.]