tag:blogger.com,1999:blog-3734925856292601239.post652147593514030635..comments2024-03-19T03:20:05.162-04:00Comments on Evo and Proud: Brain size, latitude, and ambient lightPeter Frosthttp://www.blogger.com/profile/04303172060029254340noreply@blogger.comBlogger22125tag:blogger.com,1999:blog-3734925856292601239.post-78639660815320946942011-11-18T21:52:40.526-05:002011-11-18T21:52:40.526-05:00Intelligence is working memory + long-term memory....Intelligence is working memory + long-term memory. It ISN'T visual, but can be used for visual tasks just like it can be used for anything else. Psychometrics is in a sorry state.Drive-By Posternoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-44131860765068150962011-10-10T14:39:14.353-04:002011-10-10T14:39:14.353-04:00Oh ya, I forgot to add that in my map the Japanese...Oh ya, I forgot to add that in my map the Japanese don't have smaller brains, which would have gone against the brain size - iq correlation.<br /><br />But then again i still dont know any of the actual samples.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-48960122983880162952011-10-10T00:23:56.638-04:002011-10-10T00:23:56.638-04:00I thought this would have been the most up to date...I thought this would have been the most up to date map on brain size and geography.<br /><br /> http://occidentalascent.files.wordpress.com/2010/12/beals.jpg<br /><br /> This map does not show small brains for Cambodian, which makes more sense to me. It also looks more realistic and less wild extrapolation. The one in this blog looks ridiculous around southern Germany, and the main boundary in Europe looks like an obvious extrapolation. The one I linked also has a centralized biggest brain area, instead of another extrapolated look in northern Asia and NA.<br /><br />Can someone tell me with map is more accurate and what were the data points? And why do the alps always have bigger brains, who was tested there?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-77598063795303625462011-08-21T19:40:22.496-04:002011-08-21T19:40:22.496-04:00"Chuck
Assortative mating has been document..."Chuck <br /><br />Assortative mating has been documented for both intelligence and skin color in many societies. But I doubt that there's a link between the two."<br /><br />Peter, <br /><br />1. The link would be simultaneous assortative mating for intelligence (or some correlate like SES) and light color. Are you saying that such mating patterns are unlikely? <br />Is there little link between SES and assortative mating for color? <br /><br />2. I was wondering if you could comment on the following paper:<br />Ducrest et al., (2010) "Pleiotropy in the melanocortin system, coloration and behavioural syndromes. Donald Templer cites it in "Richard Lynn and the evolution of conscientiousness." Is it plausible that there is such pleiotrophy humans?Chucknoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-43687535068515722122011-08-13T13:35:46.895-04:002011-08-13T13:35:46.895-04:00Discovered this interesting paper on orbital volum...Discovered this interesting paper on orbital volume and changes over time in Europe since the paleolithic:<br /><br />http://www.paleoanthro.org/dissertations/Michael%20Masters.pdf<br /><br />Thought it would be on interest to the topic (also seems to me to throw further doubt on their theory, based on the trends it outlines, particularly when taken with evidence relating to upper paleolithic limb adapation as an indicator of climate adaption, and other similar lines of data).Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-38054572140441110302011-08-13T11:06:26.513-04:002011-08-13T11:06:26.513-04:00Chuck and anon,
There is a correlation of about 0...Chuck and anon,<br /><br />There is a correlation of about 0.5between IQ and brain size. That's significant but not high. I agree that brain size contributes to intelligence, but intelligence is not just a matter of having more neural tissue. There must be other factors as well (myelinization?).<br /><br />Assortative mating has been documented for both intelligence and skin color in many societies. But I doubt that there's a link between the two.Peter Frostnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-64082812132482882802011-08-13T06:13:32.650-04:002011-08-13T06:13:32.650-04:00If we are talking about pure brain size actually e...If we are talking about pure brain size actually explaining IQ variation directly, rather than merely correlating with things that do (different life histories, reproductive and survival adaptations, ill health and so forth), it seems hard to explain male-female differences, or more crucially, the reported absence of any significantly decreased IQ in hypopituitary dwarfs, in whom the head is much smaller in proportion with the entire body (IQ differences proper seem only to hit primordial dwarves). <br /><br />Information storage would seem like an interesting alternate route, and obviously on a population level might correlate with IQ, but is there any empirical support for it?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-90032857035401080752011-08-13T05:02:57.824-04:002011-08-13T05:02:57.824-04:00Sexual selection reduced the size of the facial bo...Sexual selection reduced the size of the facial bones in Europeans, would that lack of facial bones not mean that that, in Europeans, eyes would have to be set deeper in the skull.<br /><br />To me it seems that black Africans' eyes are both larger and set further forward in the skull.Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-30299848004283840312011-08-12T18:24:23.916-04:002011-08-12T18:24:23.916-04:00Nix the last comment. This should say:
Bailey an...Nix the last comment. This should say:<br /><br />Bailey and Geary (2010) [6] had a related paper dealing with hominid brain evolution. The variance was explained by: population density, parasite load, latitude, and temperature. <br /><br />"I suspect bigger brains provide not so much greater intelligence as greater ability to store information. As such, they nonetheless pre-adapted northern hunter-gatherers for later advances in cultural evolution"<br /><br />So there is a copious amount of research showing 1) that brain size correlates with IQ [1], 2) that there is a sizable genetic correlation between brain size and IQ [2,3, 4], and 3) that g -- which is more than an index of storage capacity (Long term memory? What exactly do you have in mind here?) mediates the IQ-brain volume correlation [5] and yet you "suggest bigger brains provide not so much greater intelligence as greater ability to store information."<br /><br />Is that the most parsimonious explanation?Chucknoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-49915824462972898332011-08-12T17:54:09.701-04:002011-08-12T17:54:09.701-04:00Peter,
Off topic but I was thinking some more abo...Peter,<br /><br />Off topic but I was thinking some more about "colorism" and the Blacks color-IQ correlation. Reuters (1919) and Jensen (1998) suggest cross assortative mating for IQ -- and other traits -- and light color. Do you have any thoughts on that idea?Chucknoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-62860839649704249122011-08-12T17:35:27.611-04:002011-08-12T17:35:27.611-04:00There's no real difference, as far as I can se...<i><br />There's no real difference, as far as I can see, in their set between relative sizes for Indians (Indian) in the tropics and Europeans, and Chinese and other groups with flat midfaces have small eye socket to brain size volume.<br /></i><br /><br />It should also be noted that for many southern Chinese their eyeballs jut out of their face, which is likely a function of their skull shape and the lack of space in there for deep eye-sockets.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-22746467262278071972011-08-11T17:57:27.074-04:002011-08-11T17:57:27.074-04:00" although I have not measured eye-balls, it ...<i>" although I have not measured eye-balls, it appears this is false. Maybe there sample size is too small?"</i><br /><br />There's no real difference, as far as I can see, in their set between relative sizes for Indians (Indian) in the tropics and Europeans, and Chinese and other groups with flat midfaces have small eye socket to brain size volume. <br /><br />My guess is still that it's a "Caucasoids have large eye sockets as a side consequence of selection for a less tranversely flat midface, for reasons purely related to population history and/or climatic selction" issue. Note relative eye socket volume is also fairly high in the relatively tropically adapted (unless I'm wrong) but transversely not flat Abo Australians as well.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-52373195704889730022011-08-10T09:40:03.078-04:002011-08-10T09:40:03.078-04:00"The only other people with eye folds who did..."The only other people with eye folds who did not come from Asia are Subsahara Africans...San Bushmen and evwn some East Africans."<br /><br />About those East Africans, I remember I vaguely heard something about their being the descendants of the Chinese crew in Zhenghe expedition in early 15th century.<br /><br />About the bushmen I have absolutely no idea how they develop epicanthic eyefold. Thing is SEA do not really appear to have that either. epicanthic eyefold features do appear to originate from North Asia.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-15731510004887441992011-08-10T06:07:06.779-04:002011-08-10T06:07:06.779-04:00If Stephen Jay Gould had never been discredited Du...If Stephen Jay Gould had never been discredited Dunbar would still have come out with that paper? Implicit in Dunbar's hypothesis is that Gould was basically correct about cranial capacity being no guide to mental functioning. How does he show that?; by using whopping great crania - from NW Europe!<br /><br />I don't like the sound of the overcast skies hypothesis, it's too like Carlton Coon's argument that blue eyes are an adaptation which helps eysight in low light or foggy conditions.Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-39238128074804499272011-08-10T05:31:41.750-04:002011-08-10T05:31:41.750-04:00The only other people with eye folds who did not c...The only other people with eye folds who did not come from Asia are Subsahara Africans...San Bushmen and evwn some East Africans.UncleTomRuckusInGoodWhiteWorldhttps://www.blogger.com/profile/07508650487951730570noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-76582596438197985122011-08-10T05:11:39.378-04:002011-08-10T05:11:39.378-04:00"I suspect bigger brains provide not so much ..."I suspect bigger brains provide not so much greater intelligence as greater ability to store information"<br /><br />Greater ability to store information must have something to do with higher intelligence I suppose? Little is understood about how cognition works in our brain though.<br /><br />I do admit that visual representation is the easiest way for our brain to receive cognitive information, I have written an amateur article about the cognition preference <a href="http://theslittyeye.wordpress.com/2011/07/18/a-picture-is-worth-a-thousand-words/" rel="nofollow">here</a>. I do think there must be a strong relation between the capability of visual information intake and intelligence level...<br /><br />"Is this how the slit-shape eyes of Asians evolved? Did they develop as a kind of natural snow goggles?"<br /><br />The explanation for epicanthic eyefold is still debatable. Caucasoid has lived as well in high latitude regions and they do not appear to develop the epicanthic eyefold (one clear example could be the Sami in the north of Scandinavia?) Modern human Mongoloid from archaeological evidence proved to appear the latest among all other races of homo sapiens. There must be a lot of gaps needs to be filled in the evolution of Mongoloid from early homo sapiens (which I consider as the weirdest human evolution).Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-70161525235592541342011-08-10T01:03:40.428-04:002011-08-10T01:03:40.428-04:00I suspect that UncleTomRuckus... is the artist for...I suspect that UncleTomRuckus... is the artist formerly known as DragonHorse.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-79822706374740681432011-08-09T15:52:35.518-04:002011-08-09T15:52:35.518-04:00John,
Diet? How?
UncleTom,
At high latitudes, t...John,<br /><br />Diet? How?<br /><br />UncleTom,<br /><br />At high latitudes, the sample is biased toward the northwestern fringe of Europe, i.e., 18 skulls from England, France, and Scandinavia. There are only 3 skulls from northern Asia (China) and none from eastern or central Europe. In my opinion, this sample bias is responsible for the correlation between latitude and eyeball size. It's more of an "overcast sky" effect than a latitude effect.<br /><br />Tod,<br /><br />I don't think there's anything underhanded going on. People can be wrong for all kinds of reasons. It's encouraging that the authors of the study are at least looking into this phenomenon and trying to explain it.<br /><br />Anon,<br /><br />Yes, that is the most common explanation for the epicanthic eyefold.Peter Frostnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-69923457328666615422011-08-09T05:53:17.168-04:002011-08-09T05:53:17.168-04:00An Inuk wearing snow goggles. Is ambient light at ...<i>An Inuk wearing snow goggles. Is ambient light at its lowest in Inuit territory?</i><br /><br />Is this how the slit-shape eyes of Asians evolved? Did they develop as a kind of natural snow goggles?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-25541506833404129452011-08-06T16:40:09.058-04:002011-08-06T16:40:09.058-04:00It is frightening that someone as eminent as Dunba...It is frightening that someone as eminent as Dunbar would put his name to that paper.<br /><br />Dunbar has a theory that verbal communication is not for exchanging factual information but for the kind of small talk which functions as 'social grooming' to form alliances.<br /><br />Maybe his ideas about ambient light are the scientific equivalent of small talk; intended to show he is the 'right sort of chap'.<br /><br />The image says it all.Todnoreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-61078245361635716222011-08-06T16:14:49.297-04:002011-08-06T16:14:49.297-04:00This is the first time, for example, that I've...This is the first time, for example, that I've heard that Europeans have larger eyes on average than, lets say, West Africans?? Asians have larger eyes than Euros?<br /><br />I realize there are eye lid shape differences, but still. I'm African American and live in Europe, (have lived in East Asia) and although I have not measured eye-balls, it appears this is false. Maybe there sample size is too small?UncleTomRuckusInGoodWhiteWorldhttps://www.blogger.com/profile/07508650487951730570noreply@blogger.comtag:blogger.com,1999:blog-3734925856292601239.post-19278276793257360802011-08-06T13:41:47.695-04:002011-08-06T13:41:47.695-04:00As you sort of mention, it seems difficult to acce...As you sort of mention, it seems difficult to accept that light is the dominant factor here. There is much that is different, diet being obvious and perhaps more easily explainable.Johnhttps://www.blogger.com/profile/05161850700121191487noreply@blogger.com