Talk:Evolution of human intelligence

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The books listed under Further Reading were my principal sources (other than my own general knowledge) for this article. Adam 00:44, 19 November 2005 (UTC)

Ok. I changed Further Reading to References. I don't know the books, but if you think the books cover most of the material in the article, it is probably safe to remove the {{unreferenced}} . Ben T/C 10:36, 20 December 2005 (UTC)

Suggested changes[edit]

There should be more info on the minds of other great apes. Also, I was under the impression that the first state was in Sumer, about 1000 years before Egypt.

The "Human Evolution" area should be divided into two sub-areas: brain evolution, and physical evolution. Of course the brain is a physical orgajn too, but I mean "everything else" when I say "physical evolution." E.g., bipedalism, lack of fur, etc.

The title for this article should be "Human Brain Evolution," not "Hominid Intelligence." "Hominid" is more correct, as the article discusses our pre-human ancestors, but "human" isn't incorrect, and is more clear to a general audience. The article is about brain evolution, not about intelligence evolution. The two are close but not the same. And "evolution" may be implied by being in the "Human Evolution" area but we can make this more clear.

The first paragraph says, more or less, that humans are distinct from other animals because we have "the ability to reason, plan, solve..." etc. It would be better to start by saying that we have huge brains, four times bigger than our closest relatives, far bigger than we need to survive, and our huge brains should make us less able to survive. In other words, start off with a mystery: how did an anatomical feature that should have made us less successful turn out to make us so successful?

The 3rd paragraph erroneously states that Darwin believed that human evolved by natural selection. In his "Descent of Man," Darwin wrote that man evolved via sexual selection, not natural selection.

The Savannah theory for bipedal evolution is presented without mentioning alternative hypotheses, such as the aquatic ape hypothesis.

The hypothesis that hands caused our ancestors' brains to develop makes no sense, given that chimpanzees, gorillas, etc. also have hands.

The hypothesis that tool-use caused our ancestors' brains to develop is also easily discredited. The huge human brain evolved before anything but primitive tools were used.

Rather than rewrite this article, I'll write another article, entitled "Human Brain Evolution." Then let's discuss who to combine the two articles, along with other articles in this wiki-area.

    I can't find this article - did you write it?  LookingGlass 18:05, 11 June 2007 (UTC)

We need a more conprehensive discussion of the extreme controversy in the scientific community surrounding the reasons humans became sedentary and developed agriculture. Simply saying that they needed food is an amazing oversimplification, and, if I remember my college archaeology class, there is ample evidence to suggest (from studies of nutrient content of bones) that the pre-sedentary hunter/gatherers thrived with much better diets. Maybe this needs its own page...

--unsigned comment by Ben T/C 10:36, 20 December 2005 (UTC)

The claim that "the hypothesis that hands caused our ancestors' brains to develop makes no sense, given that chimpanzees, gorillas, etc. also have hands" ignores the difference between free hands (which can be used for problem-solving at any time and can evolve very great dexterity and sensitivity) and hands compromised by tree-climbing or knucklewalking (which can only be used for problem-solving a limited part of the time and cannot become very dextrous or sensitive due to the need for toughness). The claim that "the hypothesis that tool-use caused our ancestors' brains to develop is also easily discredited, The huge human brain evolved before anything but primitive tools were used" ignores both the innovative element of creating new solutions to new problems and the fact that even the development of stone age tools require an ability to investigate the causes of faliure that apes do not have. The claim that "we have huge brains, four times bigger than our closest relatives, far bigger than we need to survive, and our huge brains should make us less able to survive" ignores several factors. First is the problem-solving during early pleistocene dramatic climate change back and forth that caused the transition from Australopithecus to Homo and crossed what modern research on patients who delay the onset of the first cognitive symptoms of dementia by brain exercise show to be the limit between possibly cognitively useful brain capacity and brain capacity that is redundant from a cognitive point of view. That limit is just below half normal modern human neuron count. Some further evolution was probably driven by the need for some redundancy in case of mild brain damage and the fact that individuals varied and that it was better that ones child was born with slightly too much than with slightly too little. Further evolution of brain size was likely about the evolution of elderly storytellers needing redundant brain capacity to compensate ageing. Then recent studies actually show that people from cold climates actually have slightly larger brains than people from warm climates (no racist interpretation at all, remember that all peoples are in the insured range where size no longer matters, if they were not they would not be able to ask questions or investigate causes of faliure at all), suggesting that some fraction of it may just be to generate heat, just like many animals in cold weather have energy-costly heat production. (talk) 19:40, 17 August 2011 (UTC)Martin J Sallberg

Other species[edit]

Someone should probably explain why the phenomoen of intelligence is not as prevalent in other species, despite the advantages that it gives humans. Why don't other species have anywhere near our ability to manipulate the environment? There's a book somewhere that explains that the natural selection for intelligence is not all that great, at least when compared to teeth and muscles, and that in order for intelligence to develop, one needs to not only take into account the social aspect of natural selection, but also the (apparently) precarious survival of the "species" at the "starting stages" of inteligence development. If I could only remember what it was called, and if I only kner the theory had any merit. . . . Anyway, regardless of any teleological concerns, something had to cause it. there are five types of hominid, Austraithecus afarensis, Homo habilis, Homo erectus, Homo sapiens Neanderthalensis, and Homo sapiens sapiens. 05:20, 3 June 2006 (UTC)

Justifying this article's existence[edit]

This article needs to have a reason to exist apart from the intelligence and animal cognition articles. If the article is correct in stating that non-human hominids (wouldn't a better term be "primates"?) were not significantly more intelligent/self-aware than other animals, then the information here should be compared and merged with the animal cognition article. Thus, I put a tag requesting a citation on that fact.

There is definitely room for an article about how the development of the human difference, whatever that might be, came about, and I think that's what the editors of this article have been shooting for - thus, my request for citations on the opening sentence's claims; but a better title might be Evolutionary development of human intelligence (or cognition - some consistency in our usage of terms would be nice). GreetingsEarthling 04:31, 19 March 2007 (UTC)

Hominid or Hominan?[edit]

This article seems to be about Hominan intelligence rather than Hominid intelligence. If this article needs to exist at all (and I am very sceptical that it serves any purpose) then it should be about the intelligence of the great apes if it is about Hominid intelligence, but there is no mention of the intelligence of chimpanzees, bonobos, gorillas or orangutangs, all of which are Hominids. If it is supposed to be about the intelligence of modern humans and their extinct close relatives, then it should be called Hominan intelligence surely? Alun 10:54, 4 November 2007 (UTC)

I think an explanation could be provided in italics at the beginning of the article instead of renaming the article. --Jagz (talk) 15:29, 27 January 2008 (UTC)
or the scope could be extended to include all hominids. We have dog intelligence, pigeon intelligence, but no article on primate intelligence. This article could well do with a short section on great ape cognition. dab (𒁳) 13:10, 29 June 2008 (UTC)
I've corrected some of the annoying misuse of the term "hominid". dab (𒁳) 13:26, 29 June 2008 (UTC)

Evolution of intelligence[edit]

Maybe some of this information can be used in the article:

J. Philippe Rushton, a professor of psychology at the University of Western Ontario and the current head of the Pioneer fund, has written a controversial book called Race, Evolution, and Behavior: A Life History Perspective. Rushton claims in the book that race is a valid biological concept and that racial differences frequently arrange in a continuum of Mongoloids (Orientals, East Asians) at one extreme, Negroids (blacks, Africans) at the opposite extreme, and Caucasoids (whites, Europeans) in the middle.[1] Rushton also claims that the survival challenges of making warm clothes, building durable shelter, preserving food, and strategically hunting large animals, all selected genes for greater intelligence and social organization among the populations that migrated to cold climates.

In his 2007 book, "Avoid Boring People: Lessons From a Life in Science", James D. Watson writes, "There is no firm reason to anticipate that the intellectual capacities of peoples geographically separated in their evolution should prove to have evolved identically." "Our wanting to reserve equal powers of reason as some universal heritage of humanity will not be enough to make it so."[2]

Here is a section, "The evolutionary History of IQ", that no longer appears in the "Race and intelligence" article: [1] --Jagz (talk) 18:28, 6 April 2008 (UTC)

All peoples have redundant brain capacity. Studies of dementia show that the onset of cognitive symptoms can be delayed by brain exercise until a critical limit slightly below half normal neuron count. I agree that criticism of race and brain size studies sometimes overpoliticize and that placing east asians atop undercuts moral accusations of white supremacism, but no race and brain size study I have heard of ever claimed that any ethnicity has less than half the brain size of whites, so why care? (the dementia studies was made in countries with mostly white population). The theory that cold climates should require more smartness are easily debunked, but there is a possibility that the first proto-humans to leave Africa got a slight head start in avoiding competition and thus adapting to storytelling, but that would be a miniscule race gap in formal learning that could maximally account for 2.5 formal IQ points difference between east asians and khoisan people and less than 1 point difference between whites and blacks. And it would only matter for learning velocity and life cycle, not for absolute simulation capacity (due to the redundancy). Scientific racists often place Australian aborigines low, but the avoid competition model of course places them on par with east asians, and studies actually show that aborigines have the same extremely low frequencies of dyslexia and stuttering as east asians. (talk) 20:27, 17 August 2011 (UTC) Martin J Sallberg

Article name[edit]

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

The result of the proposal was Move. I moved Evolution of human intelligence to Evolution of human intelligence/version 2 and then Hominid intelligence to Evolution of human intelligence. Anthony Appleyard (talk) 07:01, 25 January 2009 (UTC)
The current title"hominid intelligence" is rather vague. I suggest renaming the article, the evolution of human intelligence. Wapondaponda (talk) 05:56, 17 November 2008 (UTC)

I agree. fs 12:01, 19 January 2009 (UTC)
  • Oppose In February 2008 these two articles ("Hominid intelligence" and "Evolution of human intelligence") were merged under the "Hominid intelligence" title. Since the majority of the evolution did not occur within humanity, "Evolution of human intelligence" seems inappropriate to me. The section on Homo sapiens doesn't discuss the evolution of intelligence at all. It mentions in passing the so-called "Great Leap Forward" which many, if not most, authorities regard as a primarily cultural change. How about the title "Evolution of hominid intelligence"? --Bejnar (talk) 18:13, 19 January 2009 (UTC)
The title hominid intelligence, implies a description of the intelligence of living and extinct hominids. In other words, what was the IQ of homo erectus. I would think "evolution of human intelligence" is more appropriate. It should describe the progression of the cognitive abilities from our chimpanzee like ancestors to modern human. It would still encompass non-human intelligence, because human intelligence is evolved from non-human intelligence. Wapondaponda (talk) 18:39, 19 January 2009 (UTC)
I don't agree with Bejnar's argument (which is based on the fact that evolution (of intelligence) did not occur within human existence). If that was to be accepted, then Evolution of Humans would not be appropriate either, since Humans have ancestors (as every life currently on Earth). i.e. We can discuss the evolution leading to a result since, after all, life is all-evolving. fs 19:58, 19 January 2009 (UTC)
I find teleological titles inherently problematic. --Bejnar (talk) 07:15, 20 January 2009 (UTC)
Since wikipedia is full of articles discussing evolution of species up to a point and histories of places or concepts up to a point, I find your approach a crusade. In addition I find your labeling of what I say a teleology, first inaccurate and second insulting. fs 10:37, 20 January 2009 (UTC)
Another problem is the term "hominid" does not have a single standard definition. Some definitions include the great apes and some do not. Wapondaponda (talk) 20:34, 19 January 2009 (UTC)
Why is that a problem? Just define the scope of the article in the lead. "Hominid" is generally understood, and the article can clarify any fine points. --Bejnar (talk) 07:15, 20 January 2009 (UTC)
You had added six references to the further reading section, three of them use the term "human intelligence",
  • Byrne, Richard W. (1995) The Thinking Ape: Evolutionary origins of intelligence
  • Greenspan, The First Idea: How symbols, language, and intelligence evolved from our early primate ancestors to modern humans
  • Itzkoff, Seymour W. (1983) The Form of Man: The evolutionary origins of human intelligence
  • Lynch, Gary and Granger, Richard (2008) Big Brain: The Origins and Future of Human Intelligence
  • Skoyles, John R. and Sagan, Dorion (2002) Up from Dragons: The evolution of human intelligence
  • Tobias, Phillip V. (1971) The Brain in Hominid Evolution
The preference from literature seems to be human intelligence. Wapondaponda (talk) 08:04, 20 January 2009 (UTC)
Not really, it just sells books. Can we get some comments from other editors? --Bejnar (talk) 12:53, 21 January 2009 (UTC)
It would make sense then, to go with what sells. there are 2.7 million articles on wikipedia, regular editors seem to have too much on their plate. You would probably have to work with the few who have already expressed interest. Wapondaponda (talk) 16:10, 21 January 2009 (UTC)

  • Hominid intelligenceEvolution of human intelligence —(Discuss)— More precise and in line with the subject at hand. Discussion page seems to be in agreement at the moment. However, there's also a technical problem at the moment: I can't move it myself since the other new name already exists and it appears to also have a history page. Perhaps a merge of history is also needed? Thank you. --fs 12:13, 19 January 2009 (UTC)
The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Dinosaur Intelligence[edit]

Dinosaurs were very successful animals in many ways. They were well suited to the environment. Number of Dinosaur species did walk on 2 legs, which left 2 limbs for tool use. Yet, none of the Dino species became an intelligent species like humans. What might be the reason ? Is anyone able to write a wiki article on this subject ? Photnart (talk) 01:11, 16 March 2009 (UTC).

With the Dinosaurs it was size that mattered. The bigger and stronger the animal, the more likely they were to survive as it was dog eat dog world. Though they had large brains, encephalization or brain size relative to body weight was low. Because the dinosaurs grew so large, they left a niche for smaller animals to thrive. These smaller animals didn't use size to survive, but they discovered cooperation and strength in numbers. The smaller animals were the mammals. As smaller animals, the mammals had to evolve intelligence in order to outwit other predators. Hence the neocortex which is unique to mammals, evolved. The neocortex, the seat of consciousness, is the reason mammals have more intense social lives than other genera such as reptiles or amphibians. See Dunbar's number for details.
During the time of the dinosaurs, most mammals were tiny rat-like creatures. When the asteroid struck 65 million years ago, all the large animals including the dinosaurs were wiped out. Our rat-like ancestors who were nocturnal survived the heat, radiation and dust because they spent much of their time under the ground in burrows. With the dinosaurs gone, these intelligent creatures thrived and spread over the world. Size was no longer a limitation and their brains increased further.Wapondaponda (talk) 01:49, 16 March 2009 (UTC)
  • Great, thanks Wapondaponda. If your comments can be added to one of the wikipedia articles, it will be great.Photnart (talk) 03:37, 16 March 2009 (UTC).
Apparently T-Rex had very short arms, so short that the two hands could never touch each other. Even though bipedal, T-Rex's arms were too short for any tool use. Velociraptor had longer arms than T-Rex but they were relatively short compared to apes. Wapondaponda (talk) 23:36, 29 April 2009 (UTC)
For those who believe in the theory of evolution, what matters is not how one compares different species, what matters is how a species is adapted to a niche. It doesn't matte that cougers are faster than humans or that giraffes are taller - they adapted for different niches. Humans are unique in the extent to which we have developed tool use. But I am not sure it means anything to say we are "more" intelligence than other animals. Our kind of intelligence reflects the nature of our adaptation to our niche. Other animals may have very different kinds of intelligence suited to their niches.Slrubenstein | Talk 02:53, 30 April 2009 (UTC)
It is true that different animals have adapted to their own niches. However, there is the simplistic argument that humans evolved intelligence because they walked upright which freed their hands to use tools. If that were the case then all animals that walk upright should be on an evolutionary path towards higher order intelligence. It is interesting that bipedal creatures such as dinosaurs, birds and kangaroos have never figured out that they could use their arms to hold, grasp, carry stuff around and make tools. According to the social brain hypothesis, human intelligence has its roots in primate sociality and not in bipedalism. All primates are intelligent relative to other animals but they are not bipedal. Wapondaponda (talk) 05:12, 30 April 2009 (UTC)
Who's theory is it that we evolved upright to free our hands to use tools? I know of no current scholar who believes this. Chimps do not walk upright but use some tools; our ancestors evolved upright walking millions of years before any evidence of tool use. The point remains, animals are adapted to a niche. No two species occupy the same niche. Birds are not going to evolve to fill our niche as long as we are around. They will evolve to fill their own niche. And they may be very intelligent - in terms of their niche. Slrubenstein | Talk 18:01, 30 April 2009 (UTC)

There is a BBC episode called My pet dinosaur that deals directly with the question of dinosaur intelligence and bipedalism. It is also available on youtube. Wapondaponda (talk) 01:19, 14 May 2009 (UTC)

Free hands was a necessary prequisite to evolve intelligence, but not a sufficient one. It had to be combined with suitable environmental change, one ecological opportunity growing at the same time as another was shrinking. There was very little such environmental change prior to the beginning of the pleistocene, and during the mesozoic environmental change were almost all about general life-friendliness heightening and lowering maximal animal size. But when the pleistocene came, the risk of extinction became less about size and food requirement and more about stupid specialization. This was because ice ages and interglacials created and destroyed opportunities simultaneously. The theory that sociality was the cause of the evolution of intelligence is absurd because stupid animals are easy to learn to know while smart animals are difficult to learn to know, so number of relationships are no absolute measure stick and social interaction has no hope of causing intelligence to evolve. The statistical link between complex social relationships and intelligence is best explained by the fact that smarter animals are more difficult to learn to know, which also demystifies cases of not so sociable yet smart animals such as bears, cephalopods and orangutans. What Dunbar consider to be a "stable social relationship" is a arbitrary threshold ignoring the gradual differences among animals in complexity of the personality. (talk) 20:02, 17 August 2011 (UTC)Martin J Sallberg
You may want to look into r/K selection theory for an explanation. The theory rates species on quantity vs quality in regards to reproduction. Egg laying species have a higher R rating than mammals, with K selection also selecting for intelligence. So I'd say the laying of eggs is what prevented dinosaurs from evolving into an intelligent species. So being a mammal would be the primary missing links. --Zero g (talk) 21:40, 23 August 2011 (UTC)

The r/K mammalocentrism has multiple flaws. One is the empirical research proving corvids and paracites at least as smart as Great apes and cephalopods about as smart as wolves and monkeys (based on problem-solving ability), as well as some species of lizard outperforming the average mammal (and Tanganyika cichlids are as good at figuring out deceptive strategies as chimpanzees are). Another flaw is that is assumes that the "general intelligence equals mental age and everything else is specializes skills" model applies to nonhuman animals, which modern research about critical neuron count debunks altogether. (talk) 11:49, 24 August 2011 (UTC)Martin J Sallberg

Intelligence Citations Bibliography for Articles Related to Human Intelligence[edit]

You may find it helpful while reading or editing articles to look at a bibliography of Intelligence Citations, posted for the use of all Wikipedians who have occasion to edit articles on human intelligence and related issues. I happen to have circulating access to a huge academic research library at a university with an active research program in these issues (and to another library that is one of the ten largest public library systems in the United States) and have been researching these issues since 1989. You are welcome to use these citations for your own research. You can help other Wikipedians by suggesting new sources through comments on that page. It will be extremely helpful for articles on human intelligence to edit them according to the Wikipedia standards for reliable sources for medicine-related articles, as it is important to get these issues as well verified as possible. -- WeijiBaikeBianji (talk) 14:31, 29 August 2010 (UTC)

By the way, who is watching this article recently? Does anyone have suggestions for more sources for the source list? -- WeijiBaikeBianji (talk, how I edit) 04:34, 5 November 2010 (UTC)

Chimps as models of human conflict[edit]

The following unreferenced statement was recently added:

The hypothesis that human cooperativeness evolved for creating competitive coalitions
against each other are debunked by studies of chimpanzees, which show that they
cooperate well in situations without conflict but not in situations with conflict.

Although it may be true that human cooperativeness evolved long before humans developed competitive coalitions against each other, the implication that the above hypothesis can be debunked based on chimp behavior looks doubtful to me, even if a reliable source said it. Humans split from chimps more than a million years ago and many modern human intelligence characteristics developed very recently (why are there no ruins of cities built more than 20,000 years ago?) The ways that modern humans cooperate are diverse and many smart humans avoid conflicts (including competitive sports), while many more cooperate in some conflicts and avoid others, depending on the kind of conflict. The new unreferenced sentence is too weak to be included, although the basic idea and its converse are worth quoting from reliable sources. Greensburger (talk) 18:31, 6 August 2011 (UTC)

Actually it is referenced to the tv show "Human Ape". It does not claim that humans are identical to chimps, just that the evolution of cooperation beyond ape level cannot have been competetive because competition could not heighten cooperation above ape level, even more competition would just have lowered cooperation below ape level. (talk) 19:41, 17 August 2011 (UTC) Martin J Sallberg

I agree with Greensburger, the sentence is too weak, and the reference is too weak also. Chimpanzees are not our ancestors, and cannot be used to make solid prediction about their behaviors. The sentence should be deleted. Joannamasel (talk) 13:50, 19 August 2011 (UTC)

It is not only chimpanzees. No fairly clever animal combines trustful cooperation within the group with rivalry between groups. There is a reason for it. At apelike or better problem-solving ability, members of other groups can invent ways to fake their identity (the impostor effect), and any counter-measure against it inevitably leads to suspecting ingroup individuals for being outgroup, making trust within the group incompatible with rivalry between groups. Comparative studies of humans and chimpanzees do not give any exact model of human evolution but confirm that naive dupeness is the only thing about human cooperativeness that really is uniquely human. (talk) 09:51, 22 August 2011 (UTC)Martin J Sallberg

Why sexual selection is a no-go.[edit]

Believers in the sexual selection hypothesis try to explain away the fact that both sexes are intelligent by assortative mating in at least partially monogamous relationships, but that ignores the fact that individuals who are considered less attractive can mate with other individuals who are also considered less attractive because they rather mate with each other than not mate at all. That means that sexual selection affecting both sexes can only affect separate family groups, not whole species, subspecies or even just geographical populations larger than one family group. The fact that ugly children still keep being born because ugly people choose other ugly people as mates rather than not reproducing at all is familiar from modern-day experience as well. Considering the fact that some individuals always have a minority sexual taste it is extremely unlikely verging on impossible that sexual selection caused speciation in early humans. (talk) 09:49, 22 August 2011 (UTC)Martin J Sallberg

The argument that the children of unattractive individuals choosing unattractive mates should have greater mutation load has multiple flaws that each would be fatal in and by itself. One is that what is considered attractive is arbitrary as long as it is not selected by natural selection anyway, which in itself makes such evolution ridiculously improbable and combined with the existence of cultural differences in beauty ideals completely impossible (intelligence is considered sexually unattractive in many cultures, intelligence in females is considered sexually unattractive in most of Europe and the Americas, intelligence in males is considered sexually unattractive in most of Asia, and many African cultures consider intelligence unsexy in both sexes, and yet this appears to have no genetic effect on intelligence at all). Another flaw is the fact that humans obviously cannot be characterized ass 100% pure monogamous, so assortative mating is less than efficient. (talk) 18:20, 23 August 2011 (UTC)Martin J Sallberg

There is also the fact that females already are nutriently disabled by costly pregnancy, which offsets any pressure to evolve fitness indicators should it exist anyway, as well as causing them to have less free nutrients for the purpose. Furthermore, disabling fitness indicator ornaments are supposed to first develop during puberty (because fitness indicators are supposed to increase, not decrease, the viability of the offspring), but human brains consume the most nutrients during early childhood and actually become less costly with age, which offsets the very reliability as a fitness indicator. If smart brains were such a good fitness indicator, many animals should have evolved excessive intelligence they have no practical use for, and such is not the case. (talk) 11:40, 24 August 2011 (UTC)Martin J Sallberg

What you say is original research. The sexual selection should reflect mainstream hypotheses about human intelligence (eg Miller) in the context of mainstream theories of sexual selection. Martin, you may disagree with these hypotheses and theories, but that is irrelevant. Monogamous animals do not "lack disabling ornaments altogether", and the Encyclopedia Britannica, especially without any further information on addition or entry name, would not be a sufficient source for such a sweeping generalization. Eg, see, which I am adding as a ref.Joannamasel (talk) 01:59, 27 August 2011 (UTC)

The so-called "disabling ornaments" in that monogamous bird you are referring to is not anywhere near as disabling as peacock feathers or moose antlers. The moderate crest in that monogamous seabird appears to be a species recognition signal rather than a fitness indicator. There is not a single example of a species where both sexes have a mating ornament even 25% as disabling as peacock feathers or moose antlers, and if there were one or two it would, due to its low incidence, seem like genetic drift in inbred populations rather than true sexual selection. That both sexes having highly disabling mating ornaments should be common can be conclusively dismissed by statistics alone. And furthermore, you cannot seriously claim humans are 100% monogamous. I have never heard of any scientist claiming that (the highest scientific figure I have ever read is 85%). Even if we assume that your theory was true, that would mean men were AT LEAST 15% smarter than women (on average), if not more, and that is not the case. (talk) 03:58, 28 August 2011 (UTC)Martin J Sallberg

Women who are with a less desirable partner are likely to cheat with a more desirable person, which effectively prevents speciation. Regarding both sexes being intelligent, by chance alone roughly 75% of all mutations are on the X chromosome, the only real requirement is that there is no negative selection against intelligence in women. --Zero g (talk) 02:55, 27 August 2011 (UTC)

The human brain is very nutrient-costly, so there is a negative selection factor that must have been balanced by natural selection. (talk) 03:58, 28 August 2011 (UTC)Martin J Sallberg

The obvious solution as always is as others have said to stick to reliable sources. I just want to observe that one problem with discussions about sexual selection is that many editors think that what we find attractive today is whatever our ancestors found attractive. The first humans were part of our genus, but not our species, and there is no reason to think that the way sexual selection may have functioned for those transitional species is how it might function today. Nancy Tanner and Terence Deacon both suggest (in the context of otherwise very different hypotheses) that females selected for men who were more capable of cooperative behavior with other men. (well, I guess you could argue that the same is true today - whether a man is on a football team or a surgeon, he has to be able to work in close and precise cooperation with others to succeed). Certainly, "attractive" need not be a matter of physical appearance. Slrubenstein | Talk 13:18, 27 August 2011 (UTC)

Your phrase "were more capable of cooperation" assumes that cooperation should be a specific module, which is obviously not the case since apes cooperate as well as humans in conflictless situations (just not in situations with interest conflict) meaning that the only reason why humans cooperate better than apes is that most humans are naive dupes. (talk) 04:04, 28 August 2011 (UTC)Martin J Sallberg

Successful people are also attractive and this was probably true long before money was invented. A pre-historic man who owned a hundred goats would not only be attractive as a good provider to a prospective wife, but also be successful as a result of his intelligent good judgment regarding goat breeding and regarding people with whom he did business. The goat owner would also apply his good judgment in selecting a woman who likewise used intelligent good judgment in her selection of a successful man. This selection for intelligence would not only be genetic, but also be epi-genetic through an environment that taught successful skills and judgement to their children, making them more likely to pass on their intelligence-related genes as well as their learned skills to their grandchildren and greatly increase the numbers of them that survived. There is probably a reliable source that explains this, but I do not know of any. Greensburger (talk) 18:39, 27 August 2011 (UTC)

Early humans were so rare they did not have to compete against each other, so the concept of exclusive property did not exist. And if competition did exist in early humans, that would have left us all genetically soberly sceptic and impervious to charismatic leaders and indoctrination. (talk) 03:58, 28 August 2011 (UTC)Martin J Sallberg

A number of problems[edit]

Human evolution does not break neatly into those three phases (Sahelathropus, Australopithecus, Homo). Ardipithecus is between Sahelanthropus and Australopithecus, and the Homo stages themselves (habilis, ergaster/erectus, heidelbergensis/antecessor, sapien + Neanderthal + Denisovan) are worth mentioning as each likely has a different take on intelligence.

Australopithecus appears to have made tools, before the rise of the Homo line.

The Great Leap Forward theory is somewhat speculative and may be falling out of favor, thanks largely to sites at Pinnacle Point (a 160k year old cave with microliths, silcrete knapping, use of red ochre, and shellfish consumption discovered by Curtis Marean) and others. Its probably not a good idea to write this with an implicit reliance on that theory.

Qed (talk) 21:48, 2 September 2011 (UTC)

This article is crap.[edit]

The silly assumption that intelligence lacks practical survival value seems to run as a standing theme throughout almost the whole article. It gives undue weight to social intelligence hypothesis (a hypothesis that is refuted by statistical brains making brain capacity to be about precision as opposed to bits meaning that the link between brainpower and cognition is asymptotic not linear, by the fact that individuals with more complex personalities are more difficult to learn to know meaning that maximal number of relationships cannot raise with intelligence, and the by David Attenborough documented fact that stupid herd animals that believers in social intelligence hypothesis explain away as "just congregating without social structure" actually do have social hierarchies), totally fails to mention that if intelligence was such a good fitness indicator for sexual selection the sexual selection hypothesis predict it would have evolved many times meaning that hypothesis cannot explain the apparent uniqueness of human intelligence, makes no reference to the crucial distinction between neurological-conceptual discrimination on one side and mental age on the other, no references to the ability to ask questions and investigate physical reasons, no references to redundancy in brainpower, and it treats nutritional value as a model of why intelligence evolved when in fact it is only a model of how it became possible. Furthermore, some hypotheses recur under other names, e.g. "ecological dominance/social competition" is a version of social intelligence hypothesis and "intelligence as a resistance signal" is a version of sexual selection hypothesis. It does not discuss what the controversy between recent african origin model and multiregional model means to the evolution of intelligence and transmission of knowledge. It makes no references to the possibility that some skills may be due to a removal of psychological aversions rather than improved capacity or that some aspects of behavioral modernity may be the result of emergent interaction between biological adaptation to one environment and actual upbringing in a very different environment, i.e. maladaptation. The distinction between a timescale section and a models section is absurd, it fails to cover the differences in what parts of the timescale can be explained by what models. The only good thing is that it mentions the "flexible problem solving" model at all. The whole article should be cleaned up and rewritten. (talk) 18:42, 25 November 2011 (UTC)Martin J Sallberg

Homininae section is bumpy and goofy[edit]

please rewrite.--Kid 007 (talk) 14:40, 24 December 2011 (UTC)

Completely agreed. Really the entire "History" section could use a revisiting. The following "Homo" section is equally awkward in its wording and "Homo Sapiens" is just a picture... A lot of it feels speculative and there are no citations for many of the claims.Milotoor (talk) 07:56, 9 September 2013 (UTC)

Wrong to remove "fallabilism and epigenetics" model.[edit]

"Fallabilism" means admitting mistakes and not believing in any infallability. The data on learning proving the importance of willingness to committ and admit mistakes to learn from is relevant to understand where the ability to learn came/comes from. Models of evolution based on sexual selection or social intelligence both predicts a strong unwillingness to committ and admit mistakes to learn from, making them directly counterproductive in explaining human intelligence. And the question of "why does epigenetics not have the same effect in other species" is misframed in the context. You could as well be asking why natural selection did not have the same effect in all life. Epigenetics is also context-dependent. Most animals are under too much time-stressing threat to take time to think while others, such as apes, are too entangled in social intrigue to afford committing and admitting mistakes to learn from. Human evolution can then be explained as the creation of social environments friendly to mistakes. See the article "Brain" on topic page "Psychology" on The section should be reinserted into the article, possibly under a less cryptic heading. (talk) 06:45, 7 February 2013 (UTC)Martin J Sallberg

The proposed section is original research. There are citations, but they do not back up the claims made. Where in the sexual / social selection literature is an unwillingness to admit mistakes predicted? Or a statement that "mistakes are too expensive to afford". These require careful citation. And if this is about "the creation of a social environment" friendly to mistakes, why is it not a special case of social selection?
I've put the deleted text below to facilitate discussion.Joannamasel (talk) 14:20, 7 February 2013 (UTC)
===Fallabilism and epigenetics===
The Darwinian uselessness of the high levels of human intelligence can be explained if the difference in intelligence between apes and humans is actually epigenetic rather than genetic.[4] This theory is supported by research showing the importance for learning of willingness to committ and admit mistakes to learn from,[5] neither of which can be selected by sexual selection or social brain selection since both sexual selection and social intelligence are about conditions where mistakes are too expensive to afford.

It is not social SELECTION because such a removal of intolerant intrigue requires simultaneous change in multiple individuals, as opposed to selection on random mutations that begins in only one individual. The scenario is something like a more thorough version of how the Forest Troop baboons became peaceful. (talk) 15:27, 7 February 2013 (UTC)Martin J Sallberg

By the way... you don't happen to mean fallibilism? And apart from your discussion, I insist that these sentences are too technical for an ordinary reader to understand. Lova Falk talk 19:10, 7 February 2013 (UTC)

Neanderthals are not are ancestors but companions[edit]

Though it IS true that many neanderthals mated with Cro-magnons leading to many in the modern day human population to in part have also descended from neanderthals. Neanderthals and Cro-magnons are different species which evolved around the same time from the same ancestor. So we didn't EVOLVE out off neanderthals.

Further I read somewhere that neanderthals had larger brain size but less off it was used for thinking(most for controlling their in-efficient bodies)as a result we are smarter, similar to how dolphins(while having a larger brain size) use around 80% of it for sonar and sound.

Neanderthal extinction could have been avoided by either a 25 rise or decrease in the Birth & death rates respectively. — Preceding unsigned comment added by (talk) 16:27, 5 July 2013‎ (UTC)

Hi, and thank you for your comment! How exactly would you like to change the article? Lova Falk talk 08:20, 4 August 2013 (UTC)

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