Quote Originally Posted by Satrana View Post

You are discussing variations in proportions not in structure. Our brain structures do not vary any more than other variations seen in any other organ between people. Structure and function are not variable.
But small variations can have huge effects!

Maybe they choose it for another reason say they choose a side which faces the cave entrance or faces cave wall etc. The point of my example is to show that we should be considering simple ideas to consider how behavior is formed without jumping straight to genetics to describe something that genetics does not care about. Dawkin's "The Selfish Gene" is a must read to understand that genetic code is always aimed at self preservation, it does not care about frivolous behavior that has no effect on self preservation. The question to ask is do you really believe a bat's dna instructs it which wing to favor?
Dawkins has his points but the selfish gene notion is also overly simplistic.

Again let me mention kin selection. There are plenty of explorations on the evolution of fairness and altruism even to the point of altruistic gnes where a degree of enlightened self interest can give rise to complex systems.

Ants are a darn good example as are bees, termites and the rest of the csocial insects which through millions of years have strong altruistic behaviour and non-reproducing individuals sacrificing themselves so that other ho carry their DNA can reproduce. Yes there are cheats, pseudo-queens amongst bees for example but these can only exist in a minority and still thrive.

And as for your idea on handedness, heres a good reason for a common defaukt: natural assymetry! Most biological organisms of higher orders (skipping the radial critters here) have approximate bilateral symmetry but on close inspection one eye is lower than the other, the heart is shoved to one side and one lung is larger etc etc. As such a degree of asymmetry in nuerology is to be expected. And as some people are born with the heart on the other side etc it could be that a similar but more common mechanism causes that.

I knew someone would bring this up! LOL. In this case the transgendered behavior only exists for the purposes of sex. It is a strategy which works so it is clearly advantageous and would be carried over as instinctive behavior. However outside of mating small males do not continue to pretend to be females. It is purely a clever deception strategy for mating. If only our TG nature had the same winning strategy for women
Perhaps it did once. Perhaps it does now when freed from the constraint of the social taboo. And just because the body-morphing cuttlefish do so only for reproductive advantage as far as we currently know does not mean that in humans the mechanism and effects might be different and more profound but like everything in life, its probably still about sex.

And having TG as well as gay siblings who can help raise children and look after the elderly could have given survival as well as sexual advantages to early humans.

It seems obvious today that human sexuality never was nuclear which is why such stringent marriage laws and guilt-ridden morality was needed in the first place. Yet another example where socially induced behavior rides roughshod over actual intrinsic nature.
Theres an interesting theory that a dearth of hallucinogenic plants and the discovery of alcohol intoxication led to the shift from matriarchal tribes to patriarchal civilisation and stepped power systems in which guarantee of lineage meant power and thus strict sexual control became a politically useful tool.

But we have to be careful because animal gender/sexuality behavior cannot be compared to human behavior. Our behavior is based on a unique decision making process that is not replicated in animals. Our females do not go into heat, our brains do not react to pherenomes etc. And our gender roles are complex and extend well beyond the sexual mating/child rearing behaviors.
But Bees and Ants have been argued to have emotions, decision making has been seen in a wide number of animals, Octopi being so intelligent as to have fooled investigators into thinking they had limited memories because it seemed to have to re-learn how to open jars or run mazes, till the investigators realised the octopi were playing with the investigators deliberately fooling them and hiding the extent of their abilities when they knew they were observed!

And we know humans do react to pheremones. The scent of a woman during her period can trigger others to synchronise, there is an unconcious reaction to the scent of close relatives to discourage insest and a variety of other scent-triggers of behaviour.

Humans are more complex, more deciding, less instinctive, less pheremonal. But its all a matter of degrees.

Ornagutans have artistic behaviours in the wild, A few apes have been observed making tools and teaching others their use (even birds and octopi have been discovered to have some tool use!) and elephants and dogs have been known to mourn the dead.

Since all humans live together in societies then it is guaranteed that gender roles would be created and that they would all end up being similar for the simple reason that the physical effort and time needed by women for pregnancy and child rearing necessitated they stay protected at a home base leaving all other duties to be covered by males. This is the only sensible arrangement that results from the enormous expense needed to raise children.
But mny cultures have had many different ways of handling child rearing. Some have suggested menopause evolved specifically so the grandparents could exist for improved child-rearing considering the enormous length of time we take to reach sexual maturity.

It is true we cannot know for sure but if you project these ideas forward to how we live today then would you believe there was a genetic component that made you want to go to university to secure a better paying job, or a genetic component that promotes both partners to work in order to secure a nice home in the suburbs etc. One can easily identify numerous common behaviors in our modern lifestyle but does anyone seriously believe our genes are determining our choices in such matters.
Behavioural/evolutionary psychology argues just that, that the endorphin kick we get when our brain realises it has understood something is deliberatly addictive because of the survival benefit, that our shopping behaviour comes from hunter-gatherer instincts to acrue and hoard. You might find it an interesting field.

How do our genes know what our mother's features look like to program our brains to recognize them? What I heard was babies learn the sound of their mother's voices when in the womb so can identify their mothers immediately from birth.
The idea is we have instinctive face-recognition instincts and swiftly learn our mothers face very quickly in life from what I recall.

but that is not a genetic change but a change in melanin levels.
Possibly, but it is precisely a mutation in the gene that regulates melanin that gives us our eye colour. So what caused his change in melanin? An epigenetic switch or a non-genetic cause? The answer is unknown currently.

Here is one: http://scicurious.wordpress.com/2008...brain-imaging/

Some frmi studis have suggested that conservative or liberal outlooks is hard-wried into the brain and often hereditary (it was a new scientist article, I don't recal the issue).

A quote from the article:
The results of this study have several interesting implications. First, it is the first study to show that brain responses to facial expressions in humans are influenced by the social meaning of the facial expression. A smile is not always a good thing, and our brains can tell the difference between a smile of support and a smile that is happy we lost. Also, though your amygdala does react in general to negative facial expressions, the degree of the response will depend a lot on whether or not that anger is directed at you, or on your behalf.
But in some cultures a smile is always negative and hostile. As shaking the head can mean yes and nodding can mean no. So we have a biological function related to a variable social construct. we tell the difference between positive and negative expressions even though the meanings of the expressions are culturally dependant!

And your citation shows a connection between personality and brain activity. Not a causation of which directs which. Nor about Gender! It's interesting though.

The degree to which we are adaptable is controlled by society. We are deliberately hindered in order that we behave in a predictable manner useful for the purposes of an efficient society. We will not know our full potential until everyone is allowed to be their true selves which will likely never happen as the result would be chaotic.
Interesting, and to a limted degree certainly true, but to the extent of all strongly right handed people able to turn into strongly left handed people?
That is not so certain.

I agree but that everything you say also fits the scenario that you were born without having chosen a side and thus developed as an ambidextrous baby but eventually choosing one side over the other as an older child. Unlike others your favoritism is lesser because it developed later.
But if we are so adaptable should there not be greater variety? And should we not expect cultural variation? After all in the west we right from left to right, easier for right-handers, but this is not so in many countries which nevertheless have the same right to left handers population proportions.

Again intersexed is a different case, there are obvious genetic causes behind it.
Actually not always, exposure to a drug called DES in the womb apparently sdramatically increase the chance of being Interse and/or transexual! So thats a chemical trigger there like pot setting off schizophrenia.

With TS I don't know. I can speculate that the causations behind gender identity has similar roots to the effects of being left handed such as a different approach to language skills etc. Since we know that left and right handers process data in a different manner then this will have a knock on effect on a number of behaviors. If you interpret the world differently then you are more likely to find unusual behavior which is exactly what left handers display.

Or you can believe in a gene(s) which controls both gender and handedness. Since the study only indicated a slight increase in the relationship then this again casts doubt on it being a direct genetic link but rather a side effect.
The mouse gene suggests that most things are side effects, as does hereditary schizophrenia

All we can do currently is speculate, and thats always imortant to remind everyone about.

We have the known science, and w know there is more to everything we know than the level we have currently reached.

So we may speculate and hypothesise about things based on the known-science of the moment. But it only is just ideas untill it is rigorously tested! Then that data will give us 'the truth as far as it is currently known'.

I always like to remind people when they get to caught up in being certain based on currently understood science about things yet fully explored about what the French Acadmy of Sciences said about peasant reports of meteorites.

"Rocks cannot fall from thesky, because there are no rocks in the sky".

When viewed from tomorrowt he current science of today is the laughable ignorance of yesterday.

The fact is we can't rule out genetics nor non-genetic biological cause nor environmental triggers nor choice-caused brain-wiring or a combination of these or an unknown alternative untill sufficient studies are done.

And they have hardly started on TSs, they are yet to even begin on CDs.

3. Severe mindwashing techniques have been shown to work. Homosexuals have been trained to feel physically sick at the idea of gay sex.
And it didn't make them genuinely straight! It just made them traumatised and dysfunctional!