Wikipedia:Reference desk/Archives/Science/2023 January 12

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January 12

CV vs IQ

Is there a link between CV and IQ? 2A02:908:424:9D60:943:7C6E:5202:46E8 (talk) 07:45, 12 January 2023 (UTC)

Possibly a negative relationship. CV is a function of white matter, and IQ of grey matter, right? Abductive (reasoning) 08:12, 12 January 2023 (UTC)

I'm pretty certain I've read there is a strong positive correlation, there's almost certainly lots on the web if you just search for it though the article itself doesn't seem to mention it. The article doesn't mention white or grey matter but nerves outside of the brain so I don't know where that bit in the last reply came from. NadVolum (talk) 11:21, 12 January 2023 (UTC)

I'm pretty certain I've read... I have multiple times had the experience of (1) being sure that I read a certain piece of information all over the literature, and (2) utterly failing to find a single citation when needing it for a written report. I doubt neither your sincerity nor that you have a vivid memory, but I would advise checking for an actual link.

Here’s one of my fake memories as an exercise for the reader. You can find many sources that will make the assumption that air at ambient temperature and pressure is an ideal gas (to make such or such computation). Try finding a source that justifies it: either "we can assume air to be an ideal gas, because [some theoretical argument, for instance based on lines and points in a PT diagram]", or "this and that measurement shows that air near ambient temperature or pressure roughly follows the ideal gas law". If you can, you’re better than me; for bonus points, try finding a source that goes from "near ambient pressure and temperature" to "up to 1500K and 150atm". Tigraan^{Click here for my talk page ("private" contact)} 13:29, 12 January 2023 (UTC)

The table at Compressibility_factor#Compressibility_of_air goes up to 500 bar and 1000 K. --Amble (talk) 22:56, 12 January 2023 (UTC)

Precisely: it does vary from -5% to +20%, which is more than the acceptable margin of error in many applications (many combustion papers say "we assume the ideal gas law" and print values with 1-2% error bars). In my case, I ended up doing the calculations both with the NIST coefficients in Cantera and with the ideal gas law and showing the almost-indistinguishable curves to say "see, it doesn’t matter". That it, it does not matter for the exact trajectory my use case was following in the P-T diagram, not as a general rule applicable to a wide area. Tigraan^{Click here for my talk page ("private" contact)} 13:45, 13 January 2023 (UTC)

Just to correct Abductive on one small matter, intelligence may be a function of grey matter, but IQ is an extremely tenuous measure of intelligence. It mostly measures a very narrow type of intelligence, and one whose applicability is similarly limited. --Jayron32 11:58, 12 January 2023 (UTC)

Also, even restricting the issue to IQ as measured by an IQ test, the process of answering the test items involves the collaboration of several cortical regions, and thus the exchange of signals through neuronal pathways. Compare this to people playing correspondence chess: while postal services are not known for their chess capabilities, the speedy delivery of messages will greatly facilitate the progress of the game.  --Lambiam 14:36, 12 January 2023 (UTC)

In at least some IQ tests, some items have a time limit. The original tests for the Binet scale depended heavily on this, which is not surprising, since Binet developed the test as a tool in studying the problems of "slow" children. A design goal of the WAIS tests was not to be time dependent, but in the most recent version, WAIS-IV, the items Block Design, Arithmetic, Coding and Cancellation are timed tasks. If IQ is measured using timed tests, one can expect to see the tendency that subjects whose neural signals travel faster than average score higher than average.  --Lambiam 14:26, 12 January 2023 (UTC)

Of course not. CV is only measured in myelinated nerve cells, and such cells are incapable of the flexibility required for thinking. Thinking is a function of grey matter. Abductive (reasoning) 18:00, 12 January 2023 (UTC)

What kind of argument is that? The mailman may not even know the rules of chess, but is nevertheless essential for the game to be played out. No individual cells of any stripe or colour are "capable of the flexibility required for thinking"; it is an emergent function that requires the cooperation of many types of cells. CV is measured in units of length divided by units of time.  --Lambiam 23:49, 12 January 2023 (UTC)

Perhaps if you read the Nerve conduction velocity article more closely you'd see that only myelinated axons are measured. "Myelinated" means white matter. Signals run about 200 m/s in the axons. Thinking, and the extensive rewiring required to think new things as opposed to just being a creature of reflexes, is exclusively the domain of unmyelinated cells, what we call grey matter. Signals run about 1 m/s in them. Which is why I said that, if anything, there is a trade-off between intelligence and speed. Abductive (reasoning) 01:09, 13 January 2023 (UTC)

I heard the better "instant decisions" of smart brains take milliseconds longer than average and wonder if that's pop culture BS or at least some grain of truth. A non-thorough Google seems to show different studies have different answers for IQ vs flicker fusion threshold correlation with one that used a speed-rewarding IQ test showing positive correlation. Sagittarian Milky Way (talk) 16:32, 13 January 2023 (UTC)

The trade off in grey matter is for density of nerve cells, if they used myelin they wouldn't be able to pack so densely and their connections are mostly local so they don't need tip top speed communicating. The white matter in the brain is mostly for communicating between different areas of the brain. There is no implication or reason to say that if nerve cells used for communication use myelin then grey matter will be badly affected! If a body is built well then most things will work well rather than there being some wellness cap so atheletes tend to be twits and asses and intellectuals are wimps. NadVolum (talk) 17:24, 13 January 2023 (UTC)

There's only so much room in the cranium. Abductive (reasoning) 20:27, 13 January 2023 (UTC)

If you do the maths about how much faster a signal goes with thickness of myelin then with thickness proportional to speed there is I believe absolutely no gain by having myelin in the grey matter because the increased volume means the nerves are farther apart. There must be some interesting trade off happening for the brain to have white matter connecting different parts of the brain. NadVolum (talk) 23:47, 13 January 2023 (UTC)

What would happen if everything in a nervous system could conduct at 200 m/s? Or the speed of electric signals in copper? Would time feel slow? Sagittarian Milky Way (talk) 00:37, 14 January 2023 (UTC)

So let's economize on the communication between cortical areas. Who needs communication anyway? All this cross-area chatter only distracts from thinking new things.  --Lambiam 00:09, 14 January 2023 (UTC)

You might joke but that's what the white matter is actually doing. It is cutting down the bandwidth drastically to increase the speed with which signals move between areas. The other big gain is it uses much less energy. I don't know what other tradeoffs there are but I guess there are some. We might be more intelligent but slower without it. NadVolum (talk) 08:49, 14 January 2023 (UTC)

To be clear, I was reacting to Abductive's reductive argument.  --Lambiam 23:23, 14 January 2023 (UTC)

Perhaps it would help if somebody actually looked at the literature instead of casting aspersions. I've had a quick look now using Google and it seems and earlier testing [1] agreed with me, but a later one [2] gave rather interesting and contradictory results which don't directly support me - they say 'The speed hypothesis and neurological theory of intelligence were not supported by these results', however my take is that there is something interestinghappening which deserves a bit more study. They had more mesurements but the overlap was not contradictory. The positive correlation was using the median nerve which contraols the thumb and first twofingers and the negative correlation was using the ulnar nerve which controls the fourth and fifth finger, and there was also a strange sex related difference. If there is an intelligence link it looks to me now like it probably is with how well the nerves are tuned for use. There's other links in those and on Google too if you're really interested in knowing more. NadVolum (talk) 16:50, 13 January 2023 (UTC)

Insulting species names

Can anyone give me examples of scientists naming blood-sucking/shit-eating/parasitic species after their professional rivals as an intentional diss? Or things like rats and cockroaches? Was once told this used to happen quite often, but it's not allowed these days. --

You brought it up, so you must have at least one example in mind. ←Baseball Bugs ^{What's up, Doc?} carrots→ 23:24, 12 January 2023 (UTC)

Someone can have been told that something used to be common without having been given a specific example. I have been told that it was common for pharaohs to marry their sisters, but I could not name an example. (I know I could look it up by going through articles in Category:Pharaohs and its subcategories, but a similar approach for derogatory specific epithets by going through the articles under Category:Parasites is not promising.)  --Lambiam 00:00, 13 January 2023 (UTC)

King Tut, for one. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:27, 13 January 2023 (UTC)

The name Dermophis donaldtrumpi (intended to be insulting or at least meant to be a form of protest) has been proposed but not (yet?) accepted. The name Neopalpa donaldtrumpi is accepted, but was not obviously meant to be insulting.  --Lambiam 00:08, 13 January 2023 (UTC)

Definitely insulting names, though probably not of "professional rivals" as such. ←Baseball Bugs ^{What's up, Doc?} carrots→ 04:29, 13 January 2023 (UTC)

Looking at the various lists of organisms named after people even having a sea slug or tapeworm named after one is considered an honour. Shantavira|^{feed me} 14:26, 13 January 2023 (UTC)

I don't know.. there is that 1864 publication by Parisian publisher Auguste Poulet-Malassis. A satirical hymn under the disguise of a funeral march to the glory of the Crab louse, - it's titled De profundis morpionibus, - universally - obsessively anchored in the memory of every scholar that has ever been in contact with French education or the French educated. Legend attributes it to teh great Theophile Gauthier, the one supposedly named "chicken/wrongly seated" being nonetheless the printer-publisher himself. --Askedonty (talk) 21:04, 13 January 2023 (UTC)

Aerodactylus was named after a Pokemon. 67.165.185.178 (talk) 02:52, 14 January 2023 (UTC).