meLothedestroyerofworlds

I concede to you, Yes it seems that executive function is inhibited after frontal lobe damage but it still is irrelevant to my main point. That maybe executive function and innovative problem solving may have been induced from socializing. But I don't want this to turn to ad nauseam for you or me. I have multiple other debates and discussions I am currently a part of So for now I will agree with you and simply look more into it later, But yes I did originally show that post until it started biting me in the ass, but in retrospect the link it's derived from mentions nothing of the frontal lobe still increasing but like I said that doesn't mean it's wrong. You have definitely showed me another side to our brain's evolutionary story, and truth be told I am starting to come around to the CVH a little more.

Well from your link "Van Horn et al. concluded that damage to Gage's white matter (of which they made detailed estimates) was as or more significant to Gage's mental changes than cerebral cortex (gray matter) damage. Thiebaut de Schotten et al. estimated white-matter damage in Gage and two other famous patients ("Tan" and "H.M."), concluding that these three cases "suggest that social behavior, language, and memory depend on the coordinated activity of different [brain] regions rather than single areas in the frontal or temporal lobes.Gage displayed significant changes in behavior after his injury, but the nature, extent, and duration of these changes have been difficult to establish.Only a handful of sources give direct information on what Gage was like (either before or after the accident), the mental changes described after his death were much more dramatic than anything reported while he was alive, and few sources are explicit about the period of Gage's life to which each of their various descriptions of him (which vary widely in their implied level of functional impairment) is meant to apply. Harlow described the pre-accident Gage as hard-working, responsible, and "a great favorite" with the men in his charge, his employers having regarded him as "the most efficient and capable foreman in their employ"; he also took pains to note that Gage's memory and general intelligence seemed unimpaired after the accident (outside the periods of delirium). Nonetheless these same employers, after Gage's accident, "considered the change in his mind so marked that they could not give him his place again":" Basically, like I had said before, the entire brain is needed for cognitive output, I have only found one source that says the frontal lobe has continuosly been growing. Not that it is wrong but I am skeptical, Some argued anecdotally that gage had kept his mental prowess but had lost his ability to control his impulsive social behaviors. All data on gage is near false though, so honestly using him as an example may be bad from the start and not entirely accurate. I actually have some links showing that the frontal lobe isn't as special in our evolution as we previously thought, We literally just have giant chimp brains. Even if we disregard all of that, none of your links show that he completely lost the ability to problem solve. http://www.evoanth.net/2016/09/22/human-brain-not-special-thought/

I'm still confused but that's probably my fault. I think you're just playing semantics I could provide a plethora of research showing that frontal lobe damage and other brain damage for that matter has enormous consequences on social cognition. The effects are obviously comparable to primitive social structures and so it becomes easy to see that the brain and sociality are heavily intertwined. This discussion may be going off the rails a bit. http://www.tbicommunity.org/resources/publications/professional_education_social_comm.pdf http://www.livestrong.com/article/24256-functions-frontal-lobe-brain/ http://memory.ucsf.edu/ftd/medical/anatomy/functional/single You're misunderstanding me. How do you know that the potential, the ability to innovate and problem solve did not arise from evolutionary pressures regarding complex social units. What I am telling you is that it's a no brainer survival needs drove encephalization, because it drives all evolution! but that is a incomplete and oversimplified answer I think the SBH and the CVH fill in the gaps quite symmetrically, with the SBH being the main force of the two. Here is a irrelevant/somewhat relevant link to our discussion http://www.evoanth.net/2016/10/12/brain-evolution-unique-bloodthirsty/

I thought neanderthals were less encephalized than us? http://www.evoanth.net/2016/01/28/how-similar-were-neanderthals-and-humans/ In regards to an earlier comment you made I found that humans actually had a better sense of smell than neanderthals. http://www.evoanth.net/2012/01/02/neanderthals-had-differently-shaped-brains/ But the function of this experience is still inherited is it not? Sorry I'm getting confused here, this isn't a nature vs nurture question is it? Reasoning and planning are both useful in social settings and damage to the frontal lobe does in fact inhibit social behaviors I provided evidence above in my previous post. Phineas isn't the only case is he? We may just have to agree to disagree here all the evidence I have put forward has shown that wherever innovation or intelligence is, socialization is not far behind but neither is the survival needs for both. It is my belief that both the CVH and SBH have heavily influenced our brain and bodies evolution, but the CVH is simply the secondary mechanism, both in tandem. How are you sure that potential for the skill of innovation(which may have risen in solitary effort)did not originate from a social arms race? It is indeed interesting, I'll look more into it.

"Encephalization is defined as the amount of brain mass related to an animal's total body mass. Quantifying an animal's encephalization has been argued to be directly related to that animal's level of intelligence. " https://en.wikipedia.org/wiki/Encephalization Encephalization is not equivalent to absolute brain size. By "experience driven" I hope you don't mean something lamarkian in nature but instead that homo sapiens simply had more selection pressure against them for problem solving abilities. Yes it is true that the frontal lobe would have at least some functional control over technical solutions to everyday issues in the hominid world but it also has been shown to affect social abilities and your article even claims the same: "There is no other part of the brain where lesions can cause such a wide variety of symptoms (Kolb & Wishaw, 1990). The frontal lobes are involved in motor function, problem solving, spontaneity, memory, language, initiation, judgement, impulse control, and social and sexual behavior." A quote form wikipeia "Common effects of damage to the frontal lobe are varied. Patients who have experienced frontal lobe trauma may know the appropriate response to a situation but display inappropriate responses to those same situations in "real life". Similarly, emotions that are felt may not be expressed in the face or voice. For example, someone who is feeling happy would not smile, and his or her voice would be devoid of emotion. Along the same lines, though, the person may also exhibit excessive, unwarranted displays of emotion. Depression is common in stroke patients; it affects a great number of those who have experienced one. Also common along with depression is a loss of or decrease in motivation. Someone might not want to carry out normal daily activities and would not feel "up to it". Those who are close to the person who has experienced the damage may notice that the person no longer behaves like him or herself. This personality change is characteristic of damage to the frontal lobe and was exemplified in the case of Phineas Gage. The frontal lobe is the same part of the brain that is responsible for executive functions such as planning for the future, judgment, decision-making skills, attention span, and inhibition. These functions can decrease drastically in someone whose frontal lobe is damaged." https://en.wikipedia.org/wiki/Frontal_lobe#Damage See but now your CVH has simply degenerated into a vague and dry version of itself. IT's no longer SBH vs CVH it's sexual selection vs natural selection and both were obviously intertwined tightly throughout any species' evolutionary history. it's far too simplified now. The CVH simply states that varying climates pushed our brain evolution. Which implies that our brain's evolution was driven more by who died than who had sex. This link here shows that orangutans who were more social had higher levels of problem solving skills. Hell even social isolation is worse for you than cigarettes. Your Orangutan link won't load for me. http://www.evoanth.net/2016/09/29/social-isolation-unhealthy-smoking/ http://www.evoanth.net/2016/09/15/socialising-makes-smarter/

True true. how would autists have effected hunter gatherer populations? Don't you think mental defects would be selected against? No, I said all else being equal a bigger brain comes out on top. Neanderthals were much stronger and fatter than us, not only that, but their brains were more primitively shaped. I'll have to reread those links but yes this idea seem incredibly interesting. Are you suggesting that hominids evolved varying imbalances of g? It has long been my belief that the more globular/neotenous head shapes of our ancestors was an improvement upon homo sapien idaltu and neanderthalis. I would like sources for the frontal lobe's importance in technological advancement. I'm pretty sure the entirety of the brain is involved in problem solving tasks and not just a specific area. Still an oversimplification though, As I said plenty of times before innovation isn't intelligence and all animals have some kind of adaptation for acquiring resources but our intelligence is much too broad to be pigeonholed like this. The only thing that has more of an effect than natural selection is sexual selection and social interaction would have caused a major pressure for big brains through sexual selection. http://www.davidbrin.com/neoteny1.html

Yes but autists are a small minority of the human population. What do you mean? Elaborate more. But in that sense almost all evolution is driven by survival needs. It just seems oversimplified. I agree, though innovation arises from necessity and carried by social bonds. I basically agree with everything being said here.

No I believe both are indicative of intelligence I just think it's presence is of necessity. I wouldn't underestimate our hairy cousins, friend. Chimps do have culture albeit a very simple one, they are also capable of imagination however they're not very innovative. I think the issue here is that you keep equating intelligence and innovation. Innovation arises out of necessity and sociability is simply what gives the necessary brain power to innovate. Arc is absolutely right, the ability to manipulate abstract concepts arises from social interactions through primitive forms of language. Problem solving is the side effect and we only really use it's full extent with it when it is necessary. http://www.evoanth.net/2015/05/30/chimp-culture-includes-useless-things/ http://www.evoanth.net/2013/11/09/wild-chimps-seen-hunting-with-spears/ http://www.evoanth.net/2014/03/02/how-old-is-chimp-culture-finding-the-chimp-y-chromosomal-adam/ http://www.evoanth.net/2016/02/24/do-chimps-have-imagination/ https://en.wikipedia.org/wiki/Origin_of_language#Primate_communication I agree, that is a point I hadn't realized. A lot of immature animal offspring will "play" or mimic adult like activities to help them learn. Human children do this too however their play is almost always involved in creativity with their imagination. Both social ability and climate/ resource allocation had major impacts on hominid brain size but i still think sociability is the dominant factor. https://en.wikipedia.org/wiki/Imitation#Imitation_in_animals I think cave art is a good indicator of intelligence and so is tool use, but the more complex tools by cro magnon could have been because of larger population density or numbers and not necessarily higher intelligence. I don't think neanderthals were more intelligent though I do believe neanderthals and cro magnon were still more intelligent than the average modern day humans. You have every right to be skeptical, interpreting fossil evidence can be incredibly subjective sometimes. Nevermind, Population size has a negligible effect on creative output. http://www.evoanth.net/2016/04/26/technology-evolve-not-population-size/

I agree with you for the most part. It takes intelligence to innovate but it only requires sociality for it to spread and our archaeological record shows that it progresses in the pattern expected if it was mostly influenced by cultural learning. While I agree the invention of tool sets is more than likely caused by adapting for specific climates I have already stated I do not think tool set presence nor complexity is necessarily equated with intelligence, as my prior link had suggested. I believe sociality is the best explanation for our cultural, artistic and symbolic abilities. Problem solving is more or a less a side effect, and Isn't actually our mental strong suit. Well humans have been anatomically and behaviorally modern since about 70,000- 140,000 years ago but that doesn't tell us much about the other 4 million years. Brain size isn't everything, but I do believe it is the best indicator we have in our fossil record for hominid intelligence. Are you suggested it was sort of like circuit redundancy or something? I heard a while back about a hypothesis that claimed our brains became bigger(initially) for circuit redundancy. https://arxiv.org/ftp/arxiv/papers/1312/1312.5403.pdf http://www.sciforums.com/threads/encephalization-of-early-hominids.145308/

Well my logic was that a better eye meant a better eye for detail which would help in intricate designs and complex patterning of tool formation some would argue that the levallois techniques are easily the hardest to master of any tool set. Do you think because you are able to understand a concept like relativity that you could've come up with it on your own? Not trying to insult you but innovation has a lot more to do with how information is shared and passed down than with actual intelligence. Just so you know my preference is the social hypothesis. Here is a good link in regards to how innovation relates to intelligence: http://www.evoanth.net/2016/05/19/human-success-social/ What it shows is that the process of encephalization closely mirrors the pattern that is expected if innovation is almost completely reliant on cultural and social trends of our prehistoric ancestors. https://en.wikipedia.org/wiki/Neanderthal_behavior#Language

The correlation between brain size and intelligence is between .2 to .5 I believe. Birth canal size is more or less a mutation that compensates for brain size. Climate would probably correlate much higher if it kept getting cooler during our evolution. You may be unintentionally obfuscating the question, as I said before and as the other poster insinuated if you had a pair of clones where the only difference in their comparative anatomy was one being slightly bigger brained, the bigger brained clone would be more intelligent. I do not disagree with you though, there is fossil evidence of some hominids with brain sizes similar to Lucy, but the structure of their brain was much more modern and their tool set more complex. https://pumpkinperson.com/2015/12/23/what-exactly-is-the-correlation-between-iq-and-brain-size-in-adults/ https://www.youtube.com/watch?v=nD9gtU_jdRA ^​ think that is the right youtube link please tell me if it doesn't say anything about the particular hominid. Actually my question was in regards to encephalization not human intelligence but I do equate the two so I guess it doesn't matter. Neanderthals were more advanced than us technologically until a little bit before we left Africa. I give their enhanced spatial abilities credit for that one. I n my opinion the demise of neanderthals was probably their inefficient bodies, competition with our bigger groups and interbreeding with a more genetically diverse species, we were very close in intelligence. So basically you subscribe to the Climatic variability hypothesis being the main force. Climate is correlated with resource allocation and resource allocation supplies a demand for continual development of tools and strategies. This is all assuming technological advancement is equivalent to intelligence but, I suspect this is not the case so I respectfully have to disagree with you. As I said earlier our brains are shrinking(except the frontal lobe) possibly due to self domestication and it has been shown that wolves are more intelligent than dogs, though they are less curious(which is positively correlated with intelligence.) My point is that even though now we have much more collective knowledge and technology our cro magnon and neanderthal ancestors were still more intelligent than us. http://www.evoanth.net/2016/01/28/how-similar-were-neanderthals-and-humans/ http://www.evoanth.net/2015/12/10/are-humans-smarter-than-neanderthals/ http://phys.org/news/2015-09-wolves-problem-solving-task-domesticated-dogs.html

"Essentially, brain size is experience dependent but not necessarily indicative of intelligence. Perhaps the best evidence that size doesn't confer intelligence involves our Neanderthal cousins" Yes I heard about that study, Humans themselves are smaller brained today which some speculate is due to self domestication. I wasn't saying Brain size necessarily equals intelligence. The wiring of the brain itself is also important but with everything being equal a bigger brain is smarter especially within a species' variation. Neanderthals had a disproportionately large visual cortex and orbital sockets So their intelligence probably was more spatially orientated. Us humans were possibly more social. Also I agree that I think both played a role but I wanted to know which one you think had the bigger effect. http://www.evoanth.net/2014/03/13/our-brain-is-shrinking-but-our-frontal-lobe-is-growing/

Social brain hypothesis: The idea that the brain has incrementally increased overtime as a result from sociability, is an old one basically: Hominids evolved to live in large complex groups where extra cranial space is needed to remember other's intentions, names and ideologies. They used this enlarged brain, to trick others for food, impress the female hominids, and to establish themselves within the social hierarchy. Here is a a much more detailed version of this hypothesis here: http://kreativproces.dk/http:/kreativproces.dk/wp-content/uploads/2010/08/Dunbars-tal-og-reseach.pdf Here is a study supporting the hypothesis: http://rspb.royalsocietypublishing.org/content/280/1765/20131151 Here is a study that does not support it: http://rstb.royalsocietypublishing.org/content/362/1480/561 Climatic variability hypothesis: In the past Africa and areas where ancient hominids roamed were not stable environments, proponents of this hypothesis state that it was the need to constantly adapt to an ever changing environment that caused brain size to triple. Here is a more detailed version: http://humanorigins.si.edu/research/climate-and-human-evolution/climate-effects-human-evolution Here is a study supporting the hypothesis: http://link.springer.com/article/10.1007%2Fs12110-007-9015-z Here is a study that does not: http://rstb.royalsocietypublishing.org/content/367/1599/2130 EDIT: IMO I believe both had an obvious influence over our brain's evolution but I am interesting in learning which one you guys think had the bigger effect. EDIT: Sorry the link I posted for supporting evidence of climatic variability was the wrong link I have corrected it though.

Good idea, forgive me this is my first time posting on a forum like this. Do you know how to edit posts?

Please explain the reasoning behind your choice