Could humans have evolved a parietal eye (or perhaps a "pineal eye") which then migrated to the back of the head?
It is worth saying, though tautologically true, that evolution can't do what evolution can't do, and that the genetic code for new structures and functions has to be combinatorially accessible to the evolving genome. But the modularity of genetic regulatory networks (GRNs) can produce big rearrangements at a single step: redirection of a single "pointer variable" could see hardwired data structures and algorithms evolved within one sensory/cognitive module suddenly duplicated within a new brain region. (See the idea of William Calvin and Derek Bickerton that nested syntax resulted from transposing tree structures used in arm-hand-finger coordination to vocal communication.) Alternatively, polyploid mutations can duplicate at the genetic level a whole GRN, which permits divergent evolution of recycled algorithms - the tree structures for syntax could then be modified without impairing manual dexterity.
So your point is valid, but don't underestimate the power of evolution!
It is worth saying, though tautologically true, that evolution can't do what evolution can't do, and that the genetic code for new structures and functions has to be combinatorially accessible to the evolving genome.
It is worth adding that evolution can't do most of the things that evolution could do either. At least not in one instance like that which we see.
Big rearrangements at a single step leave you with disabled individuals. That's how we didn't evolve the third eye, too.
It is certainly possible to evolve a third eye on back of the head, but that takes several steps going in different direction, a very huge number of generations, and it most certainly is extremely unlikely in such brief timeframe.
One shouldn't invoke that sort of change unless one first demonstrates that this extremely unlikely path is positively the most likely way in which nested syntax can arise. They didn't demonstrate so; they just have very strong prejudice; that's what rationalizations are.
The neuroplasticity being what it is, it appears we don't need conjunctions of multiple highly unlikely events such as this as explanation for the nested syntax.
Now I'm curious why, as far as I know, no animal has ever evolved an eye in the back of its head. You mention bipedality and descent from trees, but why wouldn't a gazelle or a fly or a small fish get an advantage from one?
Gazelle can afford to move it's eyes to sides of the head (not being a predator), the fly has near omni-directional vision.
The predators, however, have a problem - they can't move the eyes to sides of the head, because that will lose the sharp binocular vision they need to stalk the prey. So it is predatory species that would benefit the most from a rear view eye. The chameleon evolved very peculiar eyes, but that's the only solution the predatory vertebrates got.
The spookfish evolved rear view mirrors that it uses to look down and up at same time. As well, there is parietal eye, but this one is very ancient and traces all the way back to time when ancestors of those animals were more transparent and it was a straightforward adaptation to add light sensitivity to some cells in the brain.
It is extremely difficult to evolve eye on back of the head. It's rare dumb luck, it takes a lot of generations, and existing eyes don't end up duplicated (except in insects and spiders etc which apparently have more flexible coding for eyes; but even in those this kind of thing doesn't happen overnight).
The point of the example is that it is not enough to show that something is advantageous, to show that it is possible to evolve. Furthermore, thanks for bringing up the gazelles - that serves as an example of how evolution really solves the rear-view problem. It doesn't create new photosensitive modules, or replicate existing ones. It just moves the eyes to sides of the head. Keep in mind that eyes, developmentally, are modules of the brain.
The evolutionary psychologists don't take that empirical knowledge of the ways of evolution into account in any way; that's why i would say they are misusing word 'evolution' to mean 'magic'; the word evolution ought to encompass our knowledge of how evolution works, whereas the magic can do anything.
Side thought: dividing the world into predators and prey is an oversimplification. Cats, for example, are both. I'm not sure how common this is.
Prey animals generally have their eyes on the sides of their heads, which do a good job of covering all directions. And eyes are expensive -- they need a lot of brain.
The flatfish has one eye that moves to the other side of its head.
Edit: to clarify: two eyes, one of which moves to the other side of its head as it grows. Richard Dawkins is fond of this example, using it in The Blind Watchmaker and The Greatest Show On Earth.
Flies have compound eyes which allow nearly omnidirectional vision. Evolving a new eye when you've already got hair in the way is probably hard, since it would get in the way of a simple light sensitive patch as a starting point, and even if a specimen did mutate one it would probably offer a very weak advantage compared in a species that already has fully developed binocular vision and the ability to turn its head.
Some species have developed additional eyes evolving independently from their original sets though
Groups of neurons have to connect in the new ways - the neurons on one side must express binding proteins, which would guide the axons towards them; the weights of the connections have to be adjusted. Majority of the genes expressed in neurons, affect all of the neurons; some affect just a group, but there is no mechanism by which an entirely arbitrary group's bindings may be controlled from the DNA in 1 mutation. The difficulties are not unlike those of an extra eye. This, combined with above-mentioned speed constraints, imposes severe limitations on which sorts of wiring modifications, and ultimately, behaviours that humans could have evolved during the hunter gatherer environment. Even very simple things - such as preference for particular body shape of the mates - have extreme hidden implementation complexity in terms of the DNA modifications leading up to the wiring leading up to the altered preferences. Wiring the brain for a specific fallacy is anything but simple. It may not be as time consuming/impossible as adding an extra eye, but it is still no little feat.
This seems reasonable until you realize that we evolved from chimp brains to human brains during the time period in question, this is a much larger change than the minor adaptations evolutionary psychologists talk about.
It's not about size of the change, it's about the complexity of the change. Increasing the brain size by four times is not a very complex change; some minor tweaks aren't either. edit: Also, the differences between chimp and human are pretty consistent with plain increase in the volume (and number of neurons), if you control for, hmm, cultural differences. You can teach chimps sign language; chimps can use and invent tools. We do it better, of course - larger brains are more powerful, perhaps the longer childhood also helps, etc.
In support of your claim: http://www.youtube.com/watch?v=AzDLkPFjev4 (I remember reading a paper basically saying the same thing, but that was before I used evernote and now I can't find it)
So would you say the differences in behavior between wolves and dogs, or between different dog breeds, are purely the result of differences in their brain size?
No, very minor simple tweaks like up and down regulation of specific types of neurotransmitters, adjusting the values on already existent responses such as fear, agression, et cetera.
Also, the differences between chimp and human are pretty consistent with plain increase in the volume (and number of neurons), if you control for, hmm, cultural differences.
You seem to be making a mistake that a lot of people without experience programing computers make, namely that merely adding computational power without improving the algorithm is sufficient to generate (Edit: useful) new behaviors. This is especially not the case with the kind of ad hoc algorithms evolution tends to generate. You're going to need new or at least improved algorithms, and if you're evolving new algorithms, they're going to be adapted to the environment you're evolving in.
I don't think knowledge of computer programming can be applied to brains through analogies involving "adding computational power" or "improving algorithms". A computer's processor, memory, algorithms and data are strictly conceptually separate and each can be modified without causing any change to the others. That's not at all the case with a brain.
Who are you to say that I am making a mistake that a lot of people without experience programming computers make? Adjust your priors: I am successful software programmer, working in computer graphics, for quite a long time. That's how i earn my living. In my life i wrote all sorts of software (of course not literally all, but still rather significant coverage). I'd say I am not making a mistake that a lot of people with little experience programming would make.
The whole point is that evolution is not generating most of the algorithms. Evolution generated a few, including a very powerful learning algorithm, which took very long time (note that power doesn't equate to complexity; evolution itself is not very complex but is rather powerful). The very powerful learning algorithm allows to adapt to environment on-spot, as well as to the brain modifications. There are algorithms adding computer power to which allows to do 'new tricks'. The new human behaviours, too, are not all that new - different in the extent, rather than in essence. We - not even all of us, some of us - search massively larger solution spaces than chimps do, but there isn't a great deal of evidence that we do anything principally different (and especially not all humans).
edit: One other thing. We do have example of how novel modules evolve. Entire new areas of brain, like neocortex, appear - over a very large number of generations. What has happened in the small brained hominid to human evolution, though, is nothing like this. The number of generations is massively smaller, and the brain is pretty much up-scaled version of the original brain. Note that this happened against strong pressure for small brain size (childbirth difficulties)
Who are you to say that I am making a mistake that a lot of people without experience programming computers make?
He's probably a person with programming experience...
and if i apply same prior to him as he applies to me, probably a person with little programming experience. Everyday tit-for-tat reflex (that one might have evolved because its conceivable it was good through much of our on-trees existence as well, albeit i'm a bit dubious as of how the DNA would code for something like tit for tat, in mammalian brain; it would code for something that sort of works like tit for tat, with a lot of side effects, such as getting irritated, and responding in the equivalent style; [learning what to be irritated at]).
So your claim is that the human brain is adaptable enough that it can rewire itself in reasonable ways in response to sense input, but so rigid that there are no easy mutations that would correspond to some of the behavioral changes evolutionary psychologists talk about.
The brain is adaptable, but the development process isn't. You connect neurons by steering the growth cones through chemical gradients. Using the genes that affect large number of neurons at once.
Consider a centipede with, say, 40 segments. It is so flexible that it can lose a lot of legs and still walk, yet so rigid that you'll have real trouble making a mutation which affects just the 27th segment (losing legs on it), requiring a lot of generations to specialize an ancient centipede into an insect (or spider, or crustacean). Why so? Because there aren't 40 segments in the DNA, there's 5..6 cell divisions when making cells that become the segments later. You need a whole lot of regulatory genes to just start addressing the segments individually from DNA. The DNA is not a blueprint.
That being said, I do agree that brain's neuroplasticity can take advantage of some mutation that's bridging two areas of the brain. How to use the data that comes over the bridge, however, is up to neuroplasticity to figure out.
You connect neurons by steering the growth cones through chemical gradients. Using the genes that affect large number of neurons at once.
Directly effecting neural growth patterns isn't the only way for genes to effect human behavior. Consider for example, the effect on human behavior of drugs like caffeine, alcohol, anti-depressants, etc. Keep in mind any drug effect can be approximately stimulated by affecting any of the steps in the chemical cascade the drug uses.
Indeed. I'm not at all against the notion that the existing mechanisms can be adapted by evolution - whenever those are coded for. You can, most definitely, up or down regulate e.g. dopamine activity.
That is far cry from emergence of specialized modules, as per "organized into modules or mental organs, each with a specialized design that makes it an expert in one arena of interaction with the world. The modules' basic logic is specified by our genetic program. Their operation was shaped by natural selection to solve the problems of the hunting and gathering life led by our ancestors in most of our evolutionary history" (Pinker 1997a, p. 21).
Lined slate as a prior
I think a better analogy is to think of the brain as a computer that comes with an operating system and some programs pre-installed. It's possible to instal new programs, and possible although much harder to patch the operating system.
That could work, though i'm very wary of the software analogies. The software in general makes extremely poor analogy to software in form of learning algorithms like the neural networks.
The way I see it, there are certain cognitive modules - a small number of them, well identified - and instincts, emotions, reflexes. Parameters of those can be adjusted by evolution. The evolution can also adjust network properties, perhaps even with some specificity. At same time, evolution is not substantially better at creating specialized modules than at other morphology, and the pleistocene evolution to our psyche is comparable in extent to pleistocene evolution to our bodies - we could up or down regulate the anger, but we did not evolve new emotions, or new hard wired things to be angry about, or new hard-wired cognitive fallacies.
And we definitely shouldn't evoke evolution as explanation for everything, as per "Given the enormous number of adaptive problems our Pleistocene ancestors faced, Tooby and Cosmides estimate that the human mind consists of "hundreds or thousands" of such evolved modules (1995, p. 1189). Thus inspired, Evolutionary Psychologists postulate evolved modules for incest avoidance, sexual attraction, mate choice, jealousy, mate retention, allocation of parental resources, kin relations, alliance formation, aggressive threat, danger avoidance, food preferences, habitat choice, and so on for all manner of complex cognitive and behavioral functions (Tooby & Cosmides 1992, p. 110)."
(quoting from this review: http://host.uniroma3.it/progetti/kant/field/ep.htm )
When you start tabooing a phrase used by the argument you are arguing against, and rewording said argument, if that is at all effective for clarifying the situation you get accused of making strawmans. It'd be wonderful if I could taboo the word 'module' and then see what evolutionary psychologists tell in response.
But okay, i'll do that:
The gist of the evo-psych that I disagree with - and I don't even disagree with all of the evo-psych - is that the areas of neocortex are highly specialized, into hundreds, maybe thousands different patches that perform substantially different function, operating using domain specific innate knowledge that has evolved (and comes from DNA) to perform the function. The patches somehow well integrate together, albeit it is not made clear how.
There is a substantial disagreement among evolutionary psychologists as to number of, and nature of, the modules, sorry, specialized patches of the neocortex. In so much as there's such disagreement, the theories that propose smaller number of simpler adaptations should be strongly favoured because of the prior that evolution is less likely to produce more complex adaptations.
If there is a fact that gazelle sees backwards (from observed behaviour), the eyes being on the sides should be very strongly favoured over evolution of an extra eye on the back.
All I'm claiming is that we have built in biases (in the sense of inductive bias not cognitive bias) about
incest avoidance, sexual attraction, mate choice, jealousy, mate retention, allocation of parental resources, kin relations, alliance formation, aggressive threat
and that these biases are the result of evolution.
Maybe, if that had time to evolve. It is pretty ridiculous to expect this to evolve really quickly though.
Practical incest avoidance can evolve long before pleistocene, and work by smell; the jealousy can also be activated by penis detecting semen in the vagina (and inflaming by immune response, provoking much anger, or simply sending an unambiguous signal to the mind to act in jealous manner if it is a loved one). It's not a good sign if one finds that only the solutions which are hard to separate from culture do evolve.
edit: that is not to say one should search under the spotlight, but if you see a key-shape outside the spotlight there's far greater chance it is an error of visual system.
Incest avoidance probably uses imprinting.
But things like sexual jealousy use a similar mechanism that makes us feel sad if we find some we cared about died regardless of how we found out about it, and quite frankly possibly the same mechanism that causes us to believe Y after thinking about X->Y and X regardless of how we came to believe X->Y or X.
Yes, but wouldn't it be useful to have an effective, straightforward detector, to complement any detection by deductive methods of reasoning? (ala Sherlock Holmes finds that the wife is cheating at him (if he had one ofc)).
To be honest I am really dubious that DNA can code for the responses to products of high level deductive reasoning. It can code for overall proneness to depression, and proneness to anger. The deductive skills are learnt, why won't be the response learnt as well?
Yes, but wouldn't it be useful to have an effective, straightforward detector, to complement any detection by deductive methods of reasoning?
I'm not saying other methods don't exist, just describing what I believe to be the one most often used.
To be honest I am really dubious that DNA can code for the responses to products of high level deductive reasoning. It can code for overall proneness to depression, and proneness to anger. The deductive skills are learnt, why won't be the response learnt as well?
Then how come people are much more likely to get depressed in response to certain high level stimuli (e.g., loosing a job) than others (e.g., getting a promotion)?
It's impossible to have a learning system without inductive biases. Thus our initial inductive biases must be genetic. So why is it unreasonable to suppose that they've been adapted to some ancestral environment?
Then how come people are much more likely to get depressed in response to certain high level stimuli (e.g., loosing a job) than others (e.g., getting a promotion)?
Because the learned meaning of 'losing a job' and 'getting a promotion' includes learned reference to the systems that should be activated (feel good / feel bad).
edit: here. http://www.jstor.org/discover/10.2307/3812538?uid=3738480&uid=2&uid=4&sid=47698770891867
Let's pick example towards which we are neutral but majority of the world isn't: the future wife not being a virgin. Some cultures outright kill for that. edit: and another example: no underage sex, which we feel ultra strongly about but many other cultures (especially the ones that kill for not being a virgin) couldn't care less. edit: and to top that off, there's participation in killing of your own children for this reproductive 'offence', in some cultures. Note that it is not some infanticide by a male. That's destruction of a descendant on which massive amount of resources have already been spent.
So are you trying to argue that male sexual jealousy is a learned behavior?
My argument for it being genetic is that it makes sense that a selfish gene wouldn't want you to waste resources raising children that aren't your own, whereas there is no reason for selfish memes to care.
The selfish gene could try not to waste resources raising children that are not possessing the gene. That works even better.
I think it is mostly learned what to be jealous about, possibly with some evolutionary assist that is nowhere as specific as jealousy, and has a lot of side effects. Furthermore, there are cultures where the host offers wives to strangers, as a form of hospitality. Possibly to breed more wives (I just came up with evo psych explanation for this on spot).
It's awful easy to rationalize any moral system evolutionarily, that's why it isn't good science.
The selfish gene could try not to waste resources raising children that are not possessing the gene. That works even better.
I'm not sure Green-beard effects can actually occur in practice since a mutation that kept the Green beard while destroying the pathway for self-altruism would out-compete the original Green beards.
The selfish gene could try not to waste resources raising children that are not possessing the gene. That works even better.
If a single gene could do that, it probably would.
You still haven't presented any plausible explanation for why the meme of jealousy would arise at all.
What's about disliking trespass on your property in general? (edit: and use of your property) Now that definitely has evolved in animals long before serious pair bonding, and can serve the function just fine.
edit: The crux of the issue is that saying 'jealousy is evolved' is a fake explanation like phlogiston, that stops further inquiry (when further enquiry is still well warranted via the 'difficulty to evolve' based prior that is not unlike occam's razor).
edit: ahh, by the way, consider female jealousy, and the jealousy for the sake of not losing the partner.
No considerations are given for the strength of the advantage
I wish this were stressed more often. It's really easy to think up selective pressures on any trait and really hard to pin down their magnitude. This means that most armchair EP explanations have very low prior probabilities by default, even if they seem intuitively reasonable.
I disagree with you, but I approve of the habit of taking an idea that won't fit in a comment and expanding it into a post.
That being said, this post isn't fleshed out enough for Main- I think it belongs in Discussion. (Alternately, you could add links and other support for all your significant assertions.)
Can you be more specific in your disagreement. Most of what I got from the original post was the suggestion to be very suspicious of humans-evolved-complicated-brain-modules type arguments. I understand if that suspicion isn't the local consensus, but what's wrong with it?
I guess. I did not want to focus attack on specific ideas from evolutionary psychology though. But yes I need to add more citations on how DNA affects the connections between neurons.
So you can't get there from here?
Since each generation can only vary from the previous by so much; if each step along the way isn't an advantage over the previous step, then evolution doesn't go that direction.
In essence, you're saying that evolutionary psychology fails evolutionary theory. If this were the case, I really would have expected prominent evolutionary biologists to have noted it- that is the sort of evidence that would make me reconsider.
If this were the case, I really would have expected prominent evolutionary biologists to have noted it
This is one of those issues in science where the controversies are ideological in origin, so one should not put too much trust in the prevailing opinions in the academic establishment (especially publicly expressed ones).
Basically, the problem is that application of evolutionary theory to human behavior (i.e. human sociobiology) quickly leads into territory that is, from today's predominant ideological perspective, too frightful to contemplate. Some 30-40 years ago, there was a raging controversy over whether human sociobiology is a legitimate field of inquiry. Its proponents argued that it's just a regular application of evolutionary theory, while its opponents maintained that it's epistemologically flawed and at the same time motivated by evil and dangerous ideology. The former, of course, claimed in return that the latter were themselves motivated by fear of their own ideology being falsified.
As the outcome of this controversy, around two decades ago a compromise was struck. The field would be recognized as a legitimate academic discipline, but under a tacit agreement to remain limited to questions with relatively low ideological impact, and insofar as ideological spin is put on the results, it would be in a respectable direction. (The opening essay in The Adapted Mind has a pretty explicit statement of these founding principles.) Moreover, the field would be rebranded as "evolutionary psychology," abandoning the "sociobiology" moniker, which had, as a result of the prior controversies, acquired sinister connotations.
This new field has been successful in building a good public image, and some of its practitioners have become prominent and respectable public intellectuals. On the other hand, as may be expected, the more hard-line anti-sociobiology ideologues have continued to be its harsh critics, and to this day, discussion about its fundamental epistemological validity has remained an ideological battleground.
Other issue is that the evolutionary psychology escapes into describing every single behaviour as evolved, instead of considering the politically loaded option that e.g. some races can be more regulated for violence than others, as result of selective pressure, instead of evolving some nice sounding cognitive module that resolves their problems in non-violent way, or only leads to some fine grained violence. In the evolutionary psychology there's little talk of adjustment of basic pre-existing emotions.
That's more because evolutionary psychologists are more concerned with describing behavior than the details of the mechanism by which that behavior comes about.
The gazelle sees backwards by moving eyes to the sides rather than by evolving eye on back of the head.
Ignoring the mechanisms is very foolish. edit: also many of the evolutionary psychologists propose a large number of domain specific modules as a mechanism, which is akin to proposing back eye as the means by which gazelle sees backwards. The gazelle ain't going to evolve the eye on back of the head, it got 2 eyes which it can move around gradually.
http://en.wikipedia.org/wiki/Criticism_of_evolutionary_psychology#Testability
In another thread, you linked to some book, I forgot the name, there was critique from another prominent guy saying it's not how mind works. Clearly there is critique.
Do you have an explanation why do you expect considerably more complex changes to wiring in the brain, than to gross morphology, i.e. shape of organism? I honestly just don't see why it would be more common for evolution to hardwire a reflex than to make a new organ. edit: Okay, for the organs there is the argument that the existing organs are pretty damn good. Still, there's plenty of opportunity for improving e.g. human locomotion, and pressure, too, and one can clearly see how slow did the bones change shapes.
edit: ahh, now i have a great question: Why would it be so much more common to evolve some complex but hard to separate from culture psychology, than it was to evolve verifiable, simple, straightforward hardwired reflexes? There's not a single well defined, agreed upon reflex i can think of that humans have, which chimps lack. There's a lot of evo-psych stuff that is allegedly unique to us humans, evolved during our hunter gatherer times.
I think this really should nail it down WRT plausibility of evo-psych. It propositions big number of very complex psychological adaptations, over the time when no straightforward, agreed upon hard wired reflexes evolved. Not just gross morphology. Anything well identifiable at which we can look and say - okay, chimps don't have this innate reflex - and agree.
So I have two problems with your response here.
First, I don't think the really interesting evo psych is about the difference between humans and chimps. The most interesting evo psych is about ideas like coalition politics, mating behavior, and emotions which we share with chimps and with many other primates as well.
(this also brings up the related points about the major "psychological" differences between different primates, or between chimps and bonobos; these seem to clearly exist, but are hard to attribute to culture; if chimp/bonobo differences can be attributed to evo psych, why not chimp/human differences?)
The more fundamental problem I have with your response is that it seems to be placing the burden of proof on Orthonormal by asking "Given such minor anatomical differences between chimps and humans, why are you expecting huge brain differences equivalent to completely new organs?" But who's positing huge brain differences equivalent to completely new organs? Given that there are hundreds of small anatomical differences between chimps and humans, I would almost want to throw the burden of proof back at you and ask "Given all the anatomical differences between chimps and humans, why are you expecting there to be zero mental differences at all except those related to scale?"
It may be that we are thinking of different things when we say "evolutionary psychology". I agree that there's no specific novel human brain module responsible for (let's say) religion: that would be equivalent to evolving a new organ. But could the brain modules handling sex, which certainly exist in other animals and chimps, have a slight difference in humans which explains why we're more naturally monogamous or polygamous or whatever the theory is nowadays? Sure. And that's what I think evo psych is about, more than it's about saying "We must have evolved a specific religion module in the last million years!"
I've nothing against what you think evo psych is about. Clearly, the sensitivity of receptors at synaptic junctions can be altered in global manner, and clearly, the intensity of any existing process can also be adjusted - similar to how shape of human body differs from that of a chimp, so can the 'shape' of human psyche.
The argument with orthonormal is on an orthogonal subject, ha ha: the evo psych as proposed by Cosmides, Tooby, Pinker, and Symons, whom exactly propose the cognitive modules as complex as organs, in the past 1.8 millions years, and whom even draw organ analogies themselves. I'm aint making up any strawmen here.
edit: Actually i didn't even want to bring up this whole debate, that's why i didn't directly refer to any of that in my original post. I just want to make a sensible argument, people can apply it, and discard the nonsensical variations of evo psych, especially when the evo psychologists themselves make organ analogies. I'd rather attack the fallacious lines of reasoning, than specific arguments.
Oh, okay.
Are you sure they believe what you think they believe? I mean, obviously all animals have sexual behaviors, many of them very complicated and different from one another, so it would be pretty nonsensical to say humans were the first animal with a "sex behavior module" in their brains. I can't imagine someone like Cosmides & Tooby would make that mistake
Language seems like an easier mistake to make, but I agree with you that it's a modification and upscaling of existing organs rather than anything new; primates seem to have Broca's and Wernicke's areas in about the same place we do doing about the same sort of thing.
I'm not clear on what timeframe do they think the 'modules' have evolved in, but they argue for a bunch of high level ones related to cognition, as described here:
http://www.ling.upenn.edu/courses/hum100/evolutionary_psychology.html'
The argument presented here in course notes is that we have some sort of social contracts module, circa - not quite sure but rather recent - that helps us solve Wason Selection Task better - when we read off paper, mind you, in english language, better when it mentions social contracts than when its letters and numbers. Apparently we have some domain limited intelligence that does Wason Selection Task correctly using logic when it is presented as social contracts - in 75% of people, but sleeps in 75% of people when it is presented as letters and numbers. This is pretty ridiculous. The Wason selection task is a pretty regular language processing bug - you misinterpret it off carelessly as instructions to execute - flip cards with numbers, see if the even have red on the back - rather than as propositions to be tested. When you word it as something concrete, be it social contract, or testing of the medications, then people actually think beyond careless misunderstanding. In natural language, if A then B is very often misused when one wants to say iff A then B.
edit: that is to say, the field is badly suffering from lack of 'probability of evolving' prior, akin to the occam''s razor used elsewhere. The difference is more than adequately explained by a zillion causes having nothing to do with evolution and everything to do with education and culture. It's a huge give-away that you can train people to be a lot better on this and similar tasks; the 'evolved module' explanation is redundant, and on top of this is highly implausible unless one's treating evolution as magic.
The critique of testability is not the critique you're making. Can you find any prominent evolutionary biologist who makes the criticism that there wasn't enough time for language-specific structure to evolve?
The 'prominent' ones, like Dawkins, are being prominent for spending too much of their effort arguing against intelligent design.
Here, a well made summary:
The basic tenet of Evolutionary Psychology is that, just as evolution by natural selection has created morphological adaptations that are universal among humans, so it has created universal psychological adaptations. (An adaptation is a trait that has been fashioned by selection for its functional role in an organism). As Tooby and Cosmides say, "the fact that any given page out of Gray's Anatomy describes in precise anatomical detail individual humans from around the world demonstrates the pronounced monomorphism present in complex human physiological adaptations. Although we cannot directly 'see' psychological adaptations (except as described neuroanatomically), no less could be true of them" (1992, p. 38). The goal of Evolutionary Psychology, then, is to discover and describe the functioning of our psychological adaptations, which are the "proximate mechanisms" that cause our behavior (Cosmides & Tooby 1987).
So far so good, they seem to refer to morphological adaptations (as similar to psychological) when it suits them. There's where it gets really crazy though:
Since the construction of complex adaptations is a very slow process of cumulative selection, typically requiring hundreds of thousands of years, Evolutionary Psychologists argue that our psychological adaptations cannot possibly be designed for modern life. Instead, they must be designed to solve the adaptive problems faced by our hunter-gatherer ancestors in the Pleistocene, the epoch spanning 1.8 million to 10,000 years ago (Tooby & Cosmides 1990b, 1992). In other words, "the evolved structure of the human mind is adapted to the way of life of Pleistocene hunter-gatherers" (Cosmides et al. 1992, p. 5). As a result, contemporary humans frequently behave non-adaptively (that is, in ways that don't promote their reproductive success), since our Pleistocene minds are not designed to respond adaptively to agricultural, industrial, or urban lifestyles (Symons 1989, 1990, 1992).
The adaptive problems faced by our Pleistocene ancestors ranged from acquiring mates and forming social alliances to avoiding predators and inedible plant matter (Buss 1995; Tooby & Cosmides 1992). Given the diverse natures of these many problems, Evolutionary Psychologists argue, a successful solution in one problem domain cannot transfer to another domain; so each adaptive problem would have selected for the evolution of its own dedicated problem-solving mechanism (Buss 1995; Cosmides & Tooby 1987, 1994; Symons 1987, 1992; Tooby & Cosmides 1992, 1995). As Symons says, "it is no more probable that some sort of general-purpose brain/mind mechanism could solve all the behavioral problems an organism faces (find food, choose a mate, select a habitat, etc.) than it is that some sort of general-purpose organ could perform all physiological functions (pump blood, digest food, nourish an embryo, etc.)" (1992, p. 142). Thus, Evolutionary Psychologists conclude, the human mind must be "organized into modules or mental organs, each with a specialized design that makes it an expert in one arena of interaction with the world. The modules' basic logic is specified by our genetic program. Their operation was shaped by natural selection to solve the problems of the hunting and gathering life led by our ancestors in most of our evolutionary history" (Pinker 1997a, p. 21).
http://host.uniroma3.it/progetti/kant/field/ep.htm
Right. Did we see any 2 lineages evolving multiple different organs after being separated for ~180k generations? Hell frigging no, ain't no examples here, because it's off by a factor of 100 or so. We don't have yesterday's mind, we don't have roman empire's mind, we don't have caveman's mind. We have up-scaled rodent's mind. edit: or actually, we have 21th century human minds, which arises on up-scaled and tweaked rodent's brain.
edit: added link.
Anyhow, i give up. You can go on with a belief in belief however much you want. It's worse than talking with mormon preachers. They don't reference prominent theologists a whole lot. They come up with some arguments why god exist, flawed ones, but there's some effort.
The argument that cognitive structure is as difficult to evolve as a new bodily organ is your personal assertion- it's not found in the sources you cite. I understand it makes intuitive sense to you, but that doesn't count for very strong evidence unless you're better versed in evolutionary biology than all of the evolutionary psychologists.
I hate to repeat myself, but until I see some evidence besides your armchair biologizing, I'm going to consider it more likely that you're making an error of reasoning than that every evolutionary psychologist is making a catastrophic error and that no evolutionary biologist has caught it. All the more so since you haven't read any of the evidence in favor of in-born structure (beyond cortical columns) for the human brain, and especially for human language.
Can you be a little bit less meta and provide any reason what so ever why cognitive structures can be a lot (1..2 orders of magnitude) frequent to evolve than organs? No? The meta-beliefs like yours are called a belief in belief.
Also, read the link I gave, in full. It outlines the objections that significantly align with mine:
Can you be a little bit less meta and provide any reason what so ever why cognitive structures can be a lot (1..2 orders of magnitude) frequent to evolve than organs?
My priors start out pretty ignorant on just how complicated, in terms of genes, a re-wiring of the brain would be. Brains have had 500 million years to evolve, which is enough time to evolve plenty of genes that govern brain development at many levels (object and meta). If it was advantageous to be able to create new brain structures in a fairly short evolutionary time, it's possible for the genome to be structured to enable that. (And in fact, this would account for why the genome doesn't have to scale with brain size- which is the only claim I found on that website which pertains to your assertion.) Anyway, like I said, I have a fairly ignorant prior there.
But then, when I find evidence for deep structure to the brain, I can update on that evidence rather than be forced to defy the data.
I'm tapping out again, this time because the conversation is really starting to degenerate. I'll just note that if you think someone believes a claim without reason, it helps to ask them for their reasons before asserting they have none. Less Wrong isn't about who's the first to accuse whom of a bias.
Well, you were first to accuse me of ignorance, but whatever.
But it does stand that you haven't ever linked any data or made a single non-meta argument in our whole discourse up to this post, linking at most the books that are not available online. You just referred to yourself finding evidence for deep structure in the brain, without being in the slightest bit specific as to the argument at hand, which is ideally not which one of us is most biased, but whenever such data does exist.
There is one thing for you to update on: the neocortex is almost everywhere 6 layers thick. There are different regions of brain with different thickness, suited to different functions. That is, naturally, cognitive modules, performing different tasks - there is no dispute over that! (Removal of any such module is not recovered from). There is neocortex that is pretty damn uniform as far as we can see, and to top that off, compensates very well for any early (pre-pruning) injuries, and even post-pruning injuries. edit: And, now what your Occam Razor favoured hypothesis ought to be?
Be suspicious of overly bold claims in evolutionary psychology - check and mostly agreed, though see Dennett's Darwin's Dangerous Idea for something that might slightly re-inflate the idea of good ev-psych.
But I don't see how your suggestion to think about minds as "lined slates" follows. It seems to not follow even more after having read your argument. What reason do be have to think that our minds have evolved to be very flexible general learning processes? Your argument makes me imagine my mind as the opposite - after reading your argument, out brains look even more like they should be a bunch of wires, randomly attached.
In the days when Sussman was a novice, Minsky once came to him as he sat hacking at the PDP6. "What are you doing?", asked Minsky. "I am training a randomly wired neural network to play Tic Tac Toe". "Why is the net wired randomly?" asked Minsky. "I do not want it to have any preconceptions of how to play." Minsky shut his eyes: "Why do you close your eyes?" Sussman asked his teacher. "So the room will be empty." At that moment, Sussman was enlightened.
A randomly wired network still can have different number of short range vs long range connections, vertical vs horizontal connections etc.
Brain is not randomly wired; it consists of cortical columns - a basic unit replicated over the brain - and some of the wiring is very specific. The axons can very accurately find their destinations. Different areas of brain can be built with different parameters of the network organisation. There are good reasons not to adopt tabula rasa - blank slate - that's why i propose the slates prepared for specific work, in minor ways. We certainly can evolve different fur on different parts of our bodies - and so we can evolve different network properties in different areas of brain. But if you want to link specific sets of neurons in specific ways from the DNA to build a circuit that performs an evolved function - all chances are you can not do that, as there isn't any genes which express just in those neurons.
The lined slate example is to make it clear that I am not arguing in favour of complete 'tabula rasa'.
With regards to our brains being learning machines, the neuroplasticity is good evidence that parts of brain can learn the tasks not originally intended, at the levels of performance close to the normal, suggesting only minor innate specialization.
We should not expect evolution of complex psychological and cognitive adaptations in the timeframe in which, morphologically, animal bodies can only change by very little. The genetic alteration to the cognition for speech shouldn't be expected to be dramatically more complex than the alteration of vocal cords.
When humans descended from trees and became bipedal, it would have been very advantageous to have an eye or two on back of the head, for detection of predators and to protect us against being back-stabbed by fellow humans. This is why all of us have an extra eye on the back of our heads, right? Ohh, we don't. Perhaps the mate selection resulted in the poor reproductive success of the back-eyed hominids. Perhaps the tribes would kill any mutant with eyes on the back.
There are pretty solid reasons why none the above has happened, and can't happen in such timeframes. The evolution does not happen simply because the trait is beneficial, or because there's a niche to be filled. A simple alteration to the DNA has to happen, causing a morphological change which results in some reproductive improvement; then DNA has to mutate again, etc. The unrelated nearly-neutral mutations may combine resulting in an unexpected change (for example, the wolves have many genes that alter their size; random selection of genes produces approximately normal distribution of the sizes; we can rapidly select smaller dogs utilizing the existing diversity). There's no such path rapidly leading up to an eye on back of the head. The eye on back of the head didn't evolve because evolution couldn't make that adaptation.
The speed of evolution is severely limited. The ways in which evolution can work, too, are very limited. In the time in which we humans have got down from the trees, we undergone rather minor adaptation in the shape of our bodies, as evident from the fossil record - and that is the degree of change we should expect in rest of our bodies including our brains.
The correct application of evolutionary theory should be entirely unable to account for outrageous hypothetical like extra eye on back of our heads (extra eye can evolve, of course, but would take very long time). Evolution is not magic. The power of scientific theory is that it can't explain everything, but only the things which are true - that's what makes scientific theory useful for finding the things that are true, in advance of observation. That is what gives science it's predictive power. That's what differentiates science from religion. The power of not explaining the wrong things.
What do we think it would take to evolve a new innate instinct? To hard-wire a cognitive mechanism?
Groups of neurons have to connect in the new ways - the neurons on one side must express binding proteins, which would guide the axons towards them; the weights of the connections have to be adjusted. Majority of the genes expressed in neurons, affect all of the neurons; some affect just a group, but there is no known mechanism by which an entirely arbitrary group's bindings may be controlled from the DNA in 1 mutation. The difficulties are not unlike those of an extra eye. This, combined with above-mentioned speed constraints, imposes severe limitations on which sorts of wiring modifications humans could have evolved during the hunter gatherer environment, and ultimately the behaviours that could have evolved. Even very simple things - such as preference for particular body shape of the mates - have extreme hidden implementation complexity in terms of the DNA modifications leading up to the wiring leading up to the altered preferences. Wiring the brain for a specific cognitive fallacy is anything but simple. It may not always be as time consuming/impossible as adding an extra eye, but it is still no little feat.
It is extremely important to take into account the properties of evolutionary process when invoking evolution as explanation for traits and behaviours.
The evolutionary theory, as invoked in the evolutionary psychology, especially of the armchair variety, all too often is an universal explanation. It is magic that can explain anything equally well. Know of a fallacy of reasoning? Think up how it could have worked for the hunter gatherer, make a hypothesis, construct a flawed study across cultures, and publish.
No considerations are given for the strength of the advantage, for the size of 'mutation target', and for the mechanisms by which the mutation in the DNA would have resulted in the modification of the circuitry such as to result in the trait, nor to the gradual adaptability. All of that is glossed over entirely in common armchair evolutionary psychology, and unfortunately, even in the academia. The evolutionary psychology is littered with examples of traits which are alleged to have evolved over the same time during which we had barely adapted to walking upright.
It may be that when describing behaviours, a lot of complexity can be hidden into very simple-sounding concepts; and thus it seems like a good target for evolutionary explanation. But when you look at the details - the axons that have to find the targets; the gene must activate in the specific cells, but not others - there is a great deal of complexity in coding for even very simple traits.
Note: I originally did not intend to make an example of junk, for thou should not pick a strawman, but for sake of clarity, there is an example of what I would consider to be junk: the explanation of better performance at Wason Selection Task as result of evolved 'social contracts module', without a slightest consideration for what it might take, in terms of DNA, to code a Wason Selection Task solver circuit, nor for alternative plausible explanation, nor for a readily available fact that people can easily learn to solve Wason Selection Task correctly when taught - the fact which still implies general purpose learning, and the fact that high-IQ people can solve far more confusing tasks of far larger complexity, which demonstrates that the tasks can be solved in absence of specific evolved 'social contract' modules.
There is an example of non-junk: the evolutionary pressure can adjust strength of pre-existing emotions such as anger, fear, and so on, and even decrease the intelligence whenever the higher intelligence is maladaptive.
Other commonly neglected fact: the evolution is not a watchmaker, blind or not. It does not choose a solution for a problem and then work on this solution! It works on all adaptive mutations simultaneously. Evolution works on all the solutions, and the simpler changes to existing systems are much quicker to evolve. If mutation that tweaks existing system improves fitness, it will, too, be selected for, even if there was a third eye in progress.
As much as it would be more politically correct and 'moderate' for e.g. evolution of religion crowd to get their point across by arguing that the religious people have evolved specific god module which doesn't do anything but make them believe in god, than to imply that they are 'genetically stupid' in some way, the same selective pressure would also make the evolution select for non-god-specific heritable tweaks to learning, and the minor cognitive deficits, that increase religiosity.
As update for tabula rasa, picture lined writing paper; it provides some guidance for the handwriting; the horizontal lined paper is good for writing text, but not for arithmetic, the five-lines-near-eachother separated by spacing is good for writing music, and the grid paper is pretty universal. Different regions of the brain are tailored to different content; but should not be expected to themselves code different algorithms, save for few exceptions which had long time to evolve, early in vertebrate history.
edit: improved the language some. edit: specific what sort of evolutionary psychology I consider to be junk, and what I do not, albeit that was not the point of the article. The point of the article was to provide you with the notions to use to see what sorts of evolutionary psychology to consider junk, and what do not.