One reason to question the notion of specialized hardware (brains) for boys and girls is the concept of universality. The easiest, by far, way to be able to do many computations, is to create a computer that can do all computations. Similarly, the easiest way by far to create a system capable of creating a variety of kinds of knowledge, is to create one capable of creating any knowledge.

One reason to believe culture would be behind these kinds of differences is we know that our culture transmits vast quantities of knowledge to children. Far more information than is in DNA, just in terms of bits. But also in terms of importance. We also know our culture believes boys and girls are different, and treats people different for many reasons.

Do you have children? A girl and a boy? I do. I can tell you categorically that they most definitely without a doubt are 'wired' differently. Regardless of what you do. Treat them absolutely identically. Even before they have outside influences. Before they start nursery/school. Before society/friends influence them. They act very differently indeed. I didn't get that before I had kids. I thought girls liked dolls because people give girls dolls. They don't. It's a reflex. It's how they're built. Just like boys love cars and doing outside stuff.

I seriously don't know what else to say here if you think men and womens brains are identical and work the same.

Did they have any contact at all with other people? Family, friends, random strangers in grocery stores who come up to coo at your baby, etc. The first question most people ask (if it is not already obvious by the clothing) is 'girl or boy?' They then treat the child accordingly.

The way people coo and talk to boys and girls is different. The toy that they are most likely to pick up and offer to the baby differs according to gender. (So, just having both boy and girl toys available isn't enough.) They hold girls more gently, and play rougher with boys.

Oh, and, fwiw, I do have children, a boy and a girl. But, I do not think this make me an authority. More likely, having children would make me biased -- I have a vested interest in believing I treated both of my children equally. An outside observer would be more likely to see my subtle biases. In the same way, parents often favour one child, without realizing they are doing it, even when it is obvious to other people around them.

Further, you have not addressed well known exceptions to your claims, such as tomboys and males who do not love to be outdoors.

Evidence would not be the right thing to provide, because I am not predicting different human behavior than the mainstream theory, I am simply explaining the same evidence in a different way. So evidence can't resolve this dispute. (Setting aside evidence from analysis of brains which is beyond our present technology.)

Of course you may ask, when is it decided what specialization is chosen, genetically or by nurturing. Clearly we can learn and specialize on things through nurturing, but some things we are also born with, for example a language instinct. So I don't think your argument is an argument at all.

I don't know if you are a woman or a man, but one thing I notice is that women can always tell me what everybody else is talking about in a cafe. I can only concentrate on the woman I am talking to, and blank out all the other people in the room. Maybe it is a personal deficit of mine (bad hearing or whatever), but I could imagine it is a women thing (broader attention). Just an example.

The meaning of one's mind being born specialized is that either it's incapable of some functions (not universal), or it's pre-loaded with enough complexity to make some functions easier and others harder. And further, the claim has to go on to say that we don't put layers of abstraction over this and do whatever we want anyway, low level complexity be damned. Do you have an argument this is the case?

You give language instinct as an example. So, do you have any argument that our DNA contains knowledge to facilitate language in particular? But perhaps more importantly, an argument that this is done differently for different people, in such a way as to cause differences in adult personalities?

Your "image processing is not intelligence" again refutes itself: so you admit that there are some things in which brains might differ. Surely, even if some parts of the brain are universal, the ultimate development must depend on the inputs available. For example, no humans have ultrasonic "vision" like bats, because they lack the respective organs. It follows that it is possible for brains to be different, depending on the body that provides the sensory inputs.

Also, it is not clear in my opinion that apes are not intelligent.

Btw. I am still not claiming that women can not be good at maths - of course they can be, there are many examples.

I guess I am not even claiming that the difference between men and women with respect to founding startups is not cultural. But I am claiming that the culture is not arbitrary, but has evolved because of the biological preconditions. Not arbitrary means it can not simply be explained by "repression through men".

That does not follow. For example, maybe they developed language because it's very useful.

@image processing: There are things inside brains which can/do differ, the issue is what effect this has on adult minds. And personality in particular. For example, how does the difference survive layers of being interpreted to remain a difference in adults personalities?

@ "repression through men" -- My position is that culture is largely transmitted, unintentionally, through behavior of parents. Further, mothers appear to have more influence over children than fathers. And female friends appear to influence young females more than their male friends. And I think the same sorts of things are done to both male and female children, just differently.

Well if you believe that, then you admit that there is a difference between men and women (within your kind of logic).

Of course nurturing has an effect, but the fact remains that men and women are different and have to face different challenges in life. It is not only the 9 months of pregnancy - yes, men could stay at home after pregnancy (now that we have breast pumps for the milk). But there are still several other differences, as I explained elsewhere, not the least the problem of finding a mate to begin with. It is a completely different challenge for men and for women, simply because women can only have a few children, whereas men can have thousands of children in theory. So women have to be more selective etc. Again just one example, but in the sum things like that end up evoking behavioral differences.

If all behavioral differences were only the result of nurturing, then why are there no more random variations? Why are there not more societies where all boys behave like girls in our western world, and vice versa? If boys and girls really were equal except for the nurturing and their visible difference, then we should see such variations, because if a society with our boy/girl pattern is stable then the reverse would be equally stable.

Edit: I think you yourself mentioned tomboys, so there are people with reversed roles. Therefore, all else being equal, whole islands of societies should develop where roles are mirrored (because apparently the reverse strategy is being evaluated on a regular basis - so if it would be equally successful, it should from time to time become dominant). But they apparently don't develop.

Why aren't there more variations in culture on Earth? First, there is a lot of shared culture across a lot of the Earth, like Abrahamic religions. Second, perhaps the logic of the situation (e.g. men being stronger) lent itself to certain simple gender roles. If so, that isn't why they still exist today in any form. Third, the general logic of memes can create common points across cultures. Fourth, Earth is a small sample size.

Consider how much more information our culture has in it.

I know 15megs is enough to implement intelligence, but how much do you imagine is left over to throw in quirks and differences? Certainly many orders of magnitude less information than our culture has it it. Less than our personality has in it.

Also bear in mind that to write intelligence in 15 megs, you need a very good programming language. Concise, powerful, lots of libraries, very good abstraction, high level of generality. And it will be targeted towards writing powerful, general, reliable things. On the other hand, these features will be inconvenient when you want to code weird special cases and hacks, so that kind of code will take more lines to write.

You can make things up like how a hormone might umm somehow affect stuff. But that isn't an actual mechanism that goes from start to finish.

You don't have to prove that a particular mechanism is in fact the one used by our bodies. You don't need any scientific evidence. Just make one up that actually could work and makes sense.

No one has ever done that. End of story.

Meanwhile, there do exist possible explanations of how culture could account for the same phenomena (like femininity). They have no rival theories. Thus, all reasonable people should tentatively believe that kind of explanation is correct.

Apparently mechanisms exists, humans are being created from mere genes, with lots and lots of differences. I don't think I need to provide any evidence for that - just go out on the street and look at the people. Nobody looks alike, except for the twins.

May I ask you: are you a creationist? I really don't want to waste my time...

If the hormone level doesn't convince you, let's take body height: can you imagine that body height could make a difference in temper? Again, I don't know, but if there was a study showing it, I would have no trouble believing it.

There are actually studies showing that tall men earn more on average than smaller men.

The world is a complicated place...

Am I a creationist? Umm, lol. No. If I was, why would i talk about evolution of both memes and genes? Since you keep bringing up personal issues, maybe we can put them to rest: I am a very (classically) liberal person, a scientifically-oriented atheist, generally a small-l libertarian. Not a science-hating, lunatic, religious conservative.

body height might control temper? how?

a correlation between height and income doesn't imply height causes income, especially not directly.

I don't know if body height affects temper, I am just giving examples that could e plausible. For example, body height could affect the blood pressure, which would surely affect temper.

What is your challenge again, that genes can affect temper? I don't even feel the need to read any papers, really. Body height doesn't convince you, take something else, say some ugly deformation of the body. Might cause depression?

Maybe those examples sound ridiculous, but so does the notion that a butterfly on the other end of the world could affect the weather on the other side of the world. Actually I think the butterfly really is an exaggeration, but nevertheless, small changes can have big effects on the outcome in a complex system. So I don't think we even have to argue.

Oh yes, and being a woman or a man obviously has a different outcome in temper. You claim that is only cultural, but that doesn't matter: in our current environment (a ka culture), your temper is affected by being a woman or a man. Point proven.

Now, if you take a culture like that as a given, you can say that ugliness causes depression, and call it a fact. And say you've proven your point. I don't dispute the possibility of making very misleading simplifications of this sort which are true in a sense.

But if we want to explain what's going on in our world, it isn't reasonable to take culture as a fixed point. It would be much more fruitful to take our genes as a fixed point, and look at what our culture causes in the context of our genes, and how a different culture would, in that context, cause something else. Doing that, we could come up with some ways our culture should be changed.

One way to see what is the true cause, A or B, is to consider what would happen if you changed only one (at the time of its creation). So if we change genes, thousands of years ago, our culture could very well have developed to have the same results, despite the genes being quite different.

But if you change imagine our culture developing differently, then having the same genes we have today won't stop it from creating different gender stereotypes.

Are you saying that nothing causes depression? Some things apparently do cause depression. I was just giving an example - maybe it is not uglyness, then it is something else. I don't care, but it is something.

And no, uglyness does not cause depression - not getting a mate because of ugliness causes depression. But that again is at least in part biological. I know you will deny that, though, because you did so in another threat some time ago. Anyway, if we deny the biology, we could culturally train ourselves to only be attracted to apes, and humanity would die out.

I never took culture as a fixed point, in fact I pointed out several alternative cultures, both existent and hypothetical.

Now I am waiting for you to describe a hypothetical culture in which things are like you want them to be, so that we can verify that it could really work that way - or perhaps biology would get in the way.

Edit: and I don't get why you deny that being ugly causes depression - on average.

So, our culture has code to have people detect certain traits caused by genes, and act differently in their presence. Just like it detects mountains, and has people act differently in their presence. But no one goes on and on about how mountains control human personalities and determine gender differences (or mountain-raised-near differences).

I live nearby the mountains and I can tell you that people in the mountains have a very different culture from the people in the flatlands, or at least used to have. I am talking about the farmers - they have different problems to face in the mountains than in the flatlands. So I am sorry but yes, mountains control human personalities and culture.

I guess to start with, you have said living in mountain regions is correlated with different kinds of culture. But you have not said by what mechanism it causes it. Which actually is the same question I kept asking about genes. So please do answer it.

Although I guess also yes, I would have claimed that other things than genes can affect human psychology.

However, you believe that when it is understood, then we will know that genes and mountains do this thing. But how do you know what the conclusion will be, now?

Can you make up a possible mechanism of genetic causation? You don't have to prove this actual mechanism is being used, just invent one that could work.

I understand the causation up to (for genes) causing more/less of a chemical in the body, larger/smaller muscles, causing defects in the eyes or exceptionally good vision, something like that.

But how do you get from there to causing some significant effect in adult personalities? Like causing people to enjoy mountains, be republicans, or consider women bad at business.

I am not saying that women's minds are not wired for startups/maths/whatever (I don't know), but the cultural differences are rooted in biological differences. Women have babies, which is very costly. Hence they need a different mindset (more responsibility, time to take care of kids etc.), they are also very valuable to men, so they can sell their bodies as baby-making machines rather than do startups. Different options in life create different paths... Men have to do something impressive to convince women to carry their babies, hence the startup thing (high risk, but if success, there will be babies).

One of the major questions this position has to answer is: why did that selection pressure result in adapted genes instead of adapted memes?

Prima facie, it would result in adapted memes, because memes evolve faster -- they have much shorter generations.

There actually was one chapter with the theory that men go hunting to impress women (and I would be ready to make the leap and equate hunting with startupping). Gathering would be more energy efficient than hunting, but hunting allows men to come home as bigshots, make a big party, and impress lots of women. That theory was only based on one study of a primitive society, though, so I guess the evidence is not yet very strong. Just a theory... Anyway, a good book to read in my opinion.

Other than that, I am not sure I agree to your question. Men and women certainly have different genes, have they not? I think the asymmetry is inherent in the problem of growing a baby inside of your body. Perhaps it would have been possible to allow both men and women to get pregnant, but it might have been too much overhead (although there are animals that can switch gender, and come to think about it, there are human hermaphrodites).

Most animals seem to have a difference between men and women - for example the spiders that eat their mates...

Men and women do have genetic differences, which they had before culture existed. But the thing at issue is whether modern-day, high-level personality features are a genetic difference, or not.

Even without the technology there are different ways society reacts. Polygamy should in theory raise the value of women (even fewer women available per men if some men have several women). But some societies reacted by putting women behind veils and removing them from the market by force.

I can imagine a culture, for example, where men do nothing and just force women to do startups. So it definitely is possible.

What I claim, though, is that the current situation in western societies might not be due to repression of women, but due to other factors. And those stem from biological differences, which give men and women different sorts of weapons in the gender war.

As the example of life-expectancy shows, it is not clear to me that women are currently getting the worse deal.

You'll probably say the mother will want time to raise her kid. But that could equally well be true of the father -- can't you imagine a culture where fathers are expected to stay home more and raise children, and mothers aren't? There's nothing impossible about that. Or it could be treated equally.

The discussion was about men and women being different, and I still maintain that is true.

Also, I don't think pregnancy is a minor thing. 9 months is 1-2% of the working life time of a women.

Besides, other effects might come to play. There is currently another thread about it on news.yc: http://www.nytimes.com/2008/01/20/magazine/20wwln-freak-t.ht...

I think effects like that are more likely to be the cause for inequality than repression.

Anyway, isn't the whole discussion completely moot? If you don't accept anything else, then what about physical strength? Can you accept that differences in physical strength can cause differences in behavior, and certainly differences in career choices?

I must apologize, but I am tired now, and we have been talking circles for a while now. Let's let it rest (I'll read your answers, if you give any, but I don't intend to reply).

That you overlook this demonstrate the power of culture. Doing what I described violates taboos, so it's hard to imagine.

However, I think we might not disagree as much as you may think: of course, in theory, since the mind can control the body, it is conceivable to create any kind of culture. Maybe we could teach our children to only walk on legs and feet, so you could rightfully claim that "walking upright is just a cultural thing". The "richer" human societies are, the more wasteful cultural habits like that we could afford.

I am not sure that society can be reprogrammed in an arbitrary way, though. First of all, it still needs to survive, and it must be able to compete with other societies, even other animals. I think you have to take into consideration WHY culture evolved into it's current state - it has an evolutionary history. I read your statements as such that you think that it was a random whim of nature to give us our current culture. If you are convinced that men and women are equal, then there must have been a 50:50 chance for gender roles being exactly reversed. Do you agree thus far?

My claim is merely that it was not random, but that there was a bias due to the differences of men and women, which makes certain cultural habits more effective than others. As you say in your previous post, and I said somewhere else, inventions might tip the scales, and other cultural models could become viable.

Why does our culture have major gender roles that permeate people's personalities, today? It's not because it made logical sense in the past. Whether it did or not then, it does not now. And hasn't for some time. And this has been pointed out on a number of occasions. A particularly well-stated case was made by William Godwin in the 1790s.

What happened? People did not listen. They let their biases and closed-mindedness and unreasonableness get in the way of progress. That is the reason gender roles remain entrenched. If people were more thoughtful during the last few hundred years, then we wouldn't have recognizable gender roles today. That's the sort of cause I consider important and meaningful to explaining the present day situation.

Another fact of the situation is that parents teach gender roles to their children, whether the children like it or not, and without regard for whether it is helpful or hurtful, useful or not, makes sense or not, etc In a culture which does this, it isn't reasonable to say the gender roles exist because they are correct: the mechanism which perpetuates them does not depend on them being correct, and people are unwilling to change it so that it does.