New York - Another blow to male self-esteem.  Researchers say mothers alone may pass on the genes which determine a child's intellectual power, while fathers impart those genes controlling more instinctual, "primitive" mental functions.  An article in this week's New Scientist magazine says studies in mice are revealing that "the mother's genes contribute more to the development of the 'thinking' or 'executive' centres of the brain, while paternal genes have a greater impact on the development of the 'emotional' limbic brain."

Ongoing research at England's Cambridge University is exploring what scientists call "imprinted" genes, and their role in reproduction and evolution.  Imprinted genes differ from other genes in that their activation within the developing child depends upon the sex of the parent from which the gene came.  "Some imprinted genes work only if they come from the mother," the New Scientist article explains.  "The same gene is silenced if it is inherited via the sperm rather than the egg."

Cambridge scientists stumbled upon this fact in 1984, during research that sought to discover if mammals could grow into maturity when supplied with the genes of just one parent.  But they found such "androgenetic (mouse) embryos died, because certain vital genes had been switched off by the (donor) father."  Delving deeper into this phenomenon, researchers realised that certain genes controlling the development of the conscious, "higher" level of brain function - intelligence - are silenced in the paternal version, but operative in the maternal one.  Conversely, genes controlling more primitive limbic function - emotions, and the drives to eat, copulate, and compete - are silenced in the mother's genes, but activated in the father's.

In another study, Cambridge researchers examined the brain development of mouse embryos, abnormally weighted with extra amounts of the genes of either one parent or the other.  "As the embryos matured cells that carried only paternal genes accumulated in clusters scattered throughout the 'emotional' brain - the hypothalamus, the amygdala," New Scientist reports.  In embryos with maternally supplied genetic material, "cells containing only maternal genes were absent from the emotional brain.  Instead, they selectively accumulated in the brain's executive region (the seat of higher, cognitive intelligence)."

Of course mice and men do differ.  "It is very important work, and very, very promising," says Wolf Reik, who is studying the "imprinting" phenomenon at the Babraham Institute, near Cambridge.  However, he admits that, at this stage "everyone is a little bit lost as to what it really means."  But some psychologists are already trumpeting the discoveries as vindication of Freudian theory.  Christopher Badcock, author of PsychoDarwinism, believes paternal genes help build Freud's famous "id" - the instinctual, emotional, unconscious self-while the mother's genes are behind the more rational, conscious "ego".  During development, "maternal and paternal genes compete for control of behaviour," Badcock writes, "culminating in a mind divided into two conflicting parts strikingly similar to Freud's ego and id."

Whatever the psychological implications, experts believe "imprint" genes (of which only three or four have been identified so far) may number in the hundreds or thousands.  Improperly switched on or off, they could also be the cause of numerous genetically inherited diseases.  Researchers say more research may lead to ways of controlling the expression of such genes - and reversing the progress of these conditions.

Source: Reuters Friday 26 May 1998 from New Scientist 3 May 1997 pages 34 - 39

For Motherly X Chromosome, Gender Is Only the Beginning

by Natalie Angier

As May dawns and the mothers among us excitedly anticipate the clever e-cards that we soon will be linking to and the overpriced brunches that we will somehow end up paying for, the following job description may ring a familiar note:

Must be exceptionally stable yet ridiculously responsive to the needs of those around you; must be willing to trail after your loved ones, cleaning up their messes and compensating for their deficiencies and selfishness; must work twice as hard as everybody else; must accept blame for a long list of the world’s illnesses; must have a knack for shaping young minds while in no way neglecting the less glamorous tissues below; must have a high tolerance for babble and repetition; and must agree, when asked, to shut up, fade into the background and pretend you don’t exist.

As it happens, the above precis refers not only to the noble profession of motherhood to which we all owe our lives and guilt complexes.  It is also a decent character sketch of the chromosome that allows a human or any other mammal to become a mother in the first place: the X chromosome.

The X chromosome, like its shorter, stubbier but no less conspicuous counterpart, the Y chromosome, is a so-called sex chromosome, a segment of DNA entrusted with the pivotal task of sex determination.  A mammalian embryo outfitted with an X and Y chromosomal set buds into a male, while a mammal bearing a pair of X chromosomes emerges from the maternal berth with birthing options of her own.

Yet the X chromosome does much more than help specify an animal’s reproductive plumbing.  As scientists who study the chromosome lately have learned, the X is a rich repository of genes vital to brain development and could hold the key to the evolution of our particularly corrugated cortex.  Moreover, the X chromosome behaves unlike any of the other chromosomes of the body - unlike little big-man Y, certainly, but also unlike our 22 other pairs of chromosomes, the self-satisfied autosomes that constitute the rest of our genome, of the complete DNA kit packed into every cell that we carry.  It is a supple, switchbacking, multitasking gumby doll patch of the genome; and the closer you look, the more Cirque du Soleil it appears.

Although the precise details of its chemical structure and performance are only just emerging, the X chromosome has long been renowned among geneticists, who named it X not because of its shape, as is commonly presumed - the non-sex chromosomes also vaguely resemble an "X" at times during cell division - but because they were baffled by the way it held itself apart from the other chromosomal pairs.  "They called it X for unknown," said Mark T Ross of the X Chromosome Group at the Wellcome Trust Sanger Institute in Cambridge.  (When its much tinier male counterpart was finally detected, researchers simply continued down the alphabet for a name.)  Many of the diseases first understood to be hereditary were linked to X’s span, for the paradoxical reason that such conditions showed their face most often in those with just a single X to claim: men.

Scientists eventually determined that we inherit two copies of our 23,000 or so genes, one from each parent; and that these genes, these chemical guidelines for how to build and maintain a human, are scattered among the 23 pairs of chromosomes, along with unseemly amounts of apparent chemical babble.

Having two copies of every gene proves especially handy when one of those paired genes is defective, at which point the working version of the gene can step in and specify enough of the essential bodybuilding protein that the baby blooms just fine and may never know its DNA is hemi-flawed.  And here is where the Y’s petite stature looms large.  Because it holds a mere 50ish different genes against its counterpart’s 1,100, the vast majority of X-based genes have no potential pinch-hitter on the Y.  A boy who inherits from his mother an X chromosome that enfolds a faulty gene for a bloodclotting factor, say, or for a muscle protein or for a color receptor won’t find succor in the chromosomal analogue bestowed by Dad.  He will be born with hemophilia, or muscular dystrophy, or color-blindness.  But, hey, he will be a boy, for male-making is the task to which the Y chromosome is almost exclusively devoted.

In fact, it is to compensate for the monomania of the Y that the X chromosome has become such a mother of a multitasker.  Over the 300 million years of evolution, as the Y chromosome has shrugged off more of its generic genetic responsibilities in pursuit of sexual specialization, the X has had to pick up the slack.  It, too, has pawned off genes to other chromosomes.  But for those genes still in its charge, the X must double their output, to prod each gene to spool out twice the protein of an ordinary gene and thus be the solo equivalent of any twinned genes located on other, nonsexy chromosomes.

Ah, but women, who have two X chromosomes, two copies of those 1,100 genes: What of them?  With its usual Seussian sense of playfulness, evolution has opted to zeedo the hoofenanny.  In a girl’s cells, you don’t see two pleasantly active X chromosomes behaving like two ordinary nonsex chromosomes.  You see one hyperactive X chromosome, its genes busily pumping out twice the standard issue of protein, just as in a boy’s cells; and you see one X chromosome that has been largely though not wholly shut down, said Laura Carrel, a geneticist at Penn State College of Medicine.

Through an elaborate process called X inactivation, the chromosome is blanketed with a duct tape of nucleic acid.  In some cells of a woman’s body it may be the chromosome from Dad that’s muffled, while in other cells the maternal one stays mum.  Every daughter, then, is a walking mosaic of clamorous and quiet chromosomes, of fatherly sermons and maternal advice, while every son has but his mother’s voice to guide him.  Remember this, fellows: you are all mama’s boys.

Source: nytimes.com 1 May 2007

IQ Is Inherited, Suggests Twin Study

by Alison Motluk

Genes have a very strong influence over how certain parts of our brains develop, scientists in the US and Finland have found.  And the parts most influenced are those that govern our cognitive ability.  In short, you inherit your IQ.

Paul Thompson at the University of California at Los Angeles and his colleagues used MRI to scan the brains of 10 pairs of identical and 10 pairs of fraternal twins.  Identical twins have identical genes, whereas fraternal twins sharing on average half their genes.  The twins shared environments, means researchers can separate genetic and environmental factors.  The researchers found that certain regions of the brain were highly heritable.  These included language areas, known as Broca's and Wernicke's areas, and the frontal region, which, among other things, plays a huge role in cognition.

In identical twins, these areas showed a 95 to 100% correlation between one twin and the other - they were essentially the same.  The frontal structure, says Thompson, appears to be as highly influenced by genes as the most highly influenced trait we know of - fingerprints.  "It's extraordinary how similar they are," he says.  The finding suggests that environment - their experiences, what they learned in life, who they knew - played a negligible role in shaping it.

Fraternal twins were near-identical in Wernicke's area, but less similar in other areas, with about 60 to 70% correlation.  Random pairs of people would be expected to have no correlation.

Intellectual function

The study was all the more interesting in that it found that not only was this gray matter highly heritable, but it affected overall intelligence as well.  "We found that differences in frontal gray matter were significantly linked with differences in intellectual function," the authors write.

The volunteers each took a battery of tests that examined 17 separate abilities, including verbal and spatial working memory, attention tasks, verbal knowledge, motor speed and visuospatial ability.  These tests hone in on what's known as "g", the common element measured by IQ tests.  People who do well on one of these tests tend to do well on them all, says Thompson.

It is not known what exactly "g" is.  But these new findings suggest that "g" is not just a statistical abstraction, but rather, that it has a biological substrate in the brain, says Robert Plomin, of the Institute of Psychiatry in London.  Plomin has spent eight years looking for genes behind "g".  "I'm convinced that there are genes," he says, a lot of them, each with a small effect.

Stephen Kosslyn of Harvard University in Boston questions whether "g" should really be called intelligence.  "G" picks up on abilities such as being able to abstract rules or figure out how to order things according to rules.  "It's the kind of intelligence you need to do well in school," he says.  "Not what you need to do well in life."

Journal reference: Nature Neuroscience (DOI: 10.1038/nn758)

Moms' Poor Vocabulary Hurts Kids' Future

by Karen S Peterson

Mothers should "teach letters to their babies, talk out loud to them and read books to them regularly and consistently.
This is much less likely to happen when the mother is trapped on the bottom rungs of the socioeconomic ladder."

- Study co-author George Farkas
 

If a child comes from an economically deprived home with a mom who has a poor vocabulary, by the age of 3 his fate just may be sealed: he will possibly never catch up in school and have lifelong struggles with learning, a new study shows.

"Those children in our society who grow up in poverty or near poverty are adversely affected by their mother's own vocabulary deficit during their earliest years, when they are learning to speak at home," says George Farkas, a Penn State sociologist and co-author of the study.

The vocabulary gap suffered by children emerges at the earliest ages in both disadvantaged black and white homes, he says, and becomes dramatic by 36 months, Farkas says.

The problem lessens once a child is in school and comes in contact with verbal teachers and others.  "By the time the child is 6 and enters first grade, the vocabulary gap doesn't widen any further," Farkas says.  After starting school, there is "an upward-looking growth curve" for the disadvantaged kids that remains parallel with those from more middle-class homes.  But his research shows the economically deprived children never truly recover "from the damage done in the early, preschool years."  Typically, such youngsters don't read as quickly or as well.

"The first-grade teacher usually is told to get students reading by Christmas," Farkas says.  "If students come from low-income backgrounds, with a limited vocabulary and often non-standard English grammar and pronunciation, they are in a big predicament."  Not only must Mom be reasonably verbal, Farkas finds, but she must instruct "in a sufficiently warm and attractive manner so that the lesson takes."  It is, he says, "necessary for mothers to teach letters to their babies, talk out loud to them and read books to them regularly and consistently.  This is much less likely to happen when the mother is trapped on the bottom rungs of the socioeconomic ladder and is consumed by financial and emotional pressures or stresses."

Farkas analysed a variety of findings from the National Longitudinal Survey of Youth Data, which is funded in part by the federal government.  He analysed separately 3,500 white and 3,300 black children tracked periodically between ages 3 and 12, concentrating on socio-economic classes in each racial group.  His findings, he says, show the need for government policies that will reach out to the youngest children in order to create "school-readiness skills."

Educators and child development specialists have long known about the significance of early vocabulary skills, says Ted Feinberg of the National Association of School Psychologists.  "We know how critically important vocabulary is to all of the additional learning skills that are required of schoolchildren throughout their school careers," he says.  "If they do not have a solid foundation in vocabulary, it does not surprise me that they continue to lag behind."

Source: USA Today 12 April 2001

决定智商 身高 情商的父母因素  

身高是母亲的遗传大。在营养状况下的前提下，父母的遗传是决定孩子身高的主要因素，其中妈妈的身高尤其关键。妈妈长得高，孩子也大多长得比较高。

　　智力是母亲的遗传大。智力有一定的遗传性，同时受到环境、营养、教育等后天因素的影响。据科学家评估，遗传对智力的影响约占50%-60%，就遗传而言，妈妈聪明，生下的孩子大多聪明，如果是个男孩子，就会更聪明。这其中的原因在于，人类与智力有关的基因主要集中在X染色体上。女性有2个X染色体，男性只有1个，所以妈妈的智力在遗传中就占有了更重要的位置。

　　性格是父亲的遗传大。性格的形成固然有先天的成分，但主要是后影响。比较而言，爸爸的影响力会大过妈妈。其中，父爱的作用对女儿的影响更大。一位心理学家认为：“父亲在女儿的自尊感，身份感以及温柔个性的形成过程中，扮演着重要的角色。”另有一位专家提出，父亲能传授给女儿生活上的许多重要的教训和经验，使女儿的性格更加丰富多彩。　　

  相貌是父亲的遗传大。据美国心理学家克里斯坦菲德解释，可能由于父亲给予子女遗传上的特征，使婴儿的脸无论怎么看都更像父亲。这位科学家进一步解释说，这也是人类“自保”本能的一种体现，因为谁是母亲毫无疑问，而谁是父亲却没有这么肯定，所以必须像父亲，这样对婴儿有利，也可以鼓励父亲投入更多的爱。

上海万豪医院田主任介绍：实际上孩子是同时从父母那里继承各种身体要素的遗传因子。因此从妈妈或爸爸那里所获得的遗传因子的影响力是相同的，一般说来父母漂亮，孩子成年也漂亮，但也是不绝对的，这还要取决于青少年时期的身心智力发展。如果在学校里受到挫折，或在家中受到严重伤害，那么即使小时候很漂亮，大了也会变丑。相反，那些小时候难看，但受到家人社会良好照顾与教育，长大后也可变得“如花似玉”。

　　
　　决定智商的八对基因(还是八个？忘记了) 全部都是位于X染色体上面，在此先复习男女性是如何来的？
　　
　　男生是XY，X (卵)是来自母亲，Y(精子)是来自父亲。
　　
　　女生是XX，X (卵)是来自母亲，X (精子)是来自父亲。
　　
　　所以生男生女都是先生的错，不要怪罪妈妈的肚皮不争气!!!!
　　
　　请注意:
　　
　　男生是XY，所以男生的智商全部都是来自母亲的遗传，女生是XX，所以女生的智商是父亲跟母亲各有一半影响。
　　
　　因为女生的智商是父亲母亲都有影响，所以会有中和的效应。所以女生智商的分布会呈现自然分布(normal distribution)，就是倒钟状，中间最多，两边较少。
　　
　　然后男生因为是完全只受一方影响，所以男生智商分布会呈现在偏向在两个极端。也就是说，男生天才比较多，但是同时，蠢材之中也是男生特别多。
　　
　　这个故事告诉我们什么？
　　
　　1. 「你要判断一个男生聪不聪明，看他妈妈就知道了。」可是，你又要怎么判断一个男生的妈妈聪不聪明？........想不出简便的方法 .....
　　
　　2. 然后我们用机率来算：
　　
　　生男孩的机率= 1/2；生女孩的机率=1/2。
　　
　　生男孩的时候，母亲对于男孩智商的影响力 = 1
　　
　　生女孩的时候，母亲对于女孩智商的影响力 = 1/2
　　
　　所以说母亲跟父亲对于下一代智商的影响力(期望值)的比例是
　　
　　1*1/2 + 1/2*1/2 : 0*1/2 + 1/2*1/2
　　
　　= 0.75 ： 0.25
　　
　　= 3 ： 1
　　
　　= 母： 父
　　
　　所以说，如果你：
　　
　　1. 是男生，如果你觉得你很笨的话。你千万要娶一个聪明的女生来。这样你小孩翻盘的机率还有七成五，人生还是充满了希望。
　　
　　2. 是女生，如果你觉得你很笨的话，因为，你翻人家盘的机率有七成五.....啊，我不能再说了.........总之，最近天气不错，出去走走。
　　
　　3. 当你看到一个男生很聪明的时候，则，他父亲很聪明的机率是 0% (应该说，就算他父亲很聪明，也对他是没有影响的)，可是他母亲很聪明的机率是100%。 
 

Thank Dad for Drive - but Thank Mom for Brains...

综合起来看

男孩要找一个聪明高大的妻子

女孩最好找一个性格好 面貌俊朗 善良 且上进心十足的男子