Dhu is right. As Rajesh_g revealed here on IF, The Bell Curve book was written by taking the supremacist teachings of ultraracist Lynn, friend of the equally notorious and pro-eugenics Roger Pearson.
What some assumptions on IQ do not take into account is deterioration of brain pathways - that are used to doing certain functions (such as mathematical computation) - through <i>disuse</i>.
Indian muslims need not have a low IQ at all. It is neglect of certain faculties due to islamism dissuading them from it. Blind faith has that effect, as it teaches one to avoid thinking (coming up with one's own hypotheses from observations and then testing these) and instead teaches them to just accept things on say-so. Lack of imagination, and ban on most artistic tendencies. Christianism to a lesser extent also has this effect. It had it in full force in the past when it used to teach that imagination was evil. See the effect of christianism in Rome and Greece. Joseph McCabe wrote how the Roman nobility were reduced within some centuries from being incredibly literate (artistically or academically so) to having to sign their names by drawing little cross-marks. Look what happened to the Greeks after christianism. Christianism was famous for teaching that maths was "evil" paganism. (True only in the sense that it was paganism and was certainly evil from christianism POV.)
It was contact with Greco-Roman civilisation (arts, sciences, literary works) and after that with Samskritam (grammar, sciences, literary works like Shakuntala, arts) that brought thinking back to deprived christo Europe. The medieval European period was famous for no independent thoughts. People really were pack animals that quietly accepted their fate dictated by the Church and demurely did all the serf-work required of them.
Indian communities that had lost out Hindu schooling thanks to the christoBritish destroying Hindu schools nationwide have also not had the chance to keep in touch with what their ancestors had studied. Neglect of skills (disuse) results in deterioration. Entire communities - you will find that many fall in line with those mentioned in this thread - have thus been deprived in recent centuries of practise in those functions that would hike up their IQ values.
Don't like having to say this, I'm being forced into it - but it's for a good cause so I guess it's worth it - but I can tell from my own mathematical (in)ability these days that those of my faculties that dealt with maths have simply deteriorated through utter disuse. In the field I'm working on, all but the most basic of maths is simply unnecessary and so I've had no cause to use them. I cannot do the kind of complex equations I learnt in the latter years of high school anymore. I would have to reacquaint myself with them now and do a bit of practising to get myself into that pattern of thinking again, before my abilities of earlier years return to any acceptable degree. I've even become slow in some basic maths that I used to take no time over. Simply lost that edge I once had from not keeping in touch. From British doco, brain pathways are maintained when one keeps reusing them (by practise). It's just like a sportsman needs to keep in training in order to achieve what he could before.
In my defense, I will say that it is not just me. Two of my friends have admitted to the same sometime in the last year, and I have noticed a similar effect of reduced mathematical ability in others - people I've known since math class in high school. I'm somewhat good at the particular field of work I do now, but the toll is that I'm not that good in other things I was reasonably good at before I specialised so. (Oddly enough, I'm still not that bad in some languages, even though I'm woefully out of touch, in that I can still read books/watch films in them. Or maybe merely watching and reading keeps me in practise.)
But I know that for a brief time I had to relearn some late high school level maths in order to solve a problem, and then I was able to regain my former abilities for the period that I kept in touch with it. (Since then, they've dwindled again. Sadly.) Surely, this is true of all people, various Hindu communities or people from the rest of the world.
Like they say, nothing keeps your brain young and avoids/keeps at bay the occurrence of deteriorating brain-diseases at an older age like keeping the brain in practise by, say, playing intelligence/memory games. Studies have advised this for people getting older.
But it is true in the more general case as well. What is lost through disuse (in our case, caused by christoBritish or islamic invasions) is something that can be regained. Centuries of disruption may take some time/some generations to completely rebuild though.
It also explains how come the amazing S American capacity for urban-civilisation building is not reflected in their present IQ. They have been reduced to outsiders living in the outskirts of their own country, they have been deprived of the knowledge that used to be passed down from generation-to-generation in their ancestors' times. Therefore, their present IQ is not indicative of what they could be capable of again if they retrain themselves.
<b>ADDED:</b>
My grandfather's free time was devoted entirely to teaching all the children in the village our languages, sciences and of course math. These kids included all the Hindu communities in the village (included kids of Harijan communities :missionary-gasp).
According to my dad, the kids were all very adept and everyone excelled when they went to college (my grandfather always kept track of his students' accomplishments and it was a matter of great pleasure for him to tell us that not a single one of his students had ever failed a subject - his Gurudakshina).
But what do my grandfather and dad know really. They were only dark S Indian Hindoos.
What some assumptions on IQ do not take into account is deterioration of brain pathways - that are used to doing certain functions (such as mathematical computation) - through <i>disuse</i>.
Indian muslims need not have a low IQ at all. It is neglect of certain faculties due to islamism dissuading them from it. Blind faith has that effect, as it teaches one to avoid thinking (coming up with one's own hypotheses from observations and then testing these) and instead teaches them to just accept things on say-so. Lack of imagination, and ban on most artistic tendencies. Christianism to a lesser extent also has this effect. It had it in full force in the past when it used to teach that imagination was evil. See the effect of christianism in Rome and Greece. Joseph McCabe wrote how the Roman nobility were reduced within some centuries from being incredibly literate (artistically or academically so) to having to sign their names by drawing little cross-marks. Look what happened to the Greeks after christianism. Christianism was famous for teaching that maths was "evil" paganism. (True only in the sense that it was paganism and was certainly evil from christianism POV.)
It was contact with Greco-Roman civilisation (arts, sciences, literary works) and after that with Samskritam (grammar, sciences, literary works like Shakuntala, arts) that brought thinking back to deprived christo Europe. The medieval European period was famous for no independent thoughts. People really were pack animals that quietly accepted their fate dictated by the Church and demurely did all the serf-work required of them.
Indian communities that had lost out Hindu schooling thanks to the christoBritish destroying Hindu schools nationwide have also not had the chance to keep in touch with what their ancestors had studied. Neglect of skills (disuse) results in deterioration. Entire communities - you will find that many fall in line with those mentioned in this thread - have thus been deprived in recent centuries of practise in those functions that would hike up their IQ values.
Don't like having to say this, I'm being forced into it - but it's for a good cause so I guess it's worth it - but I can tell from my own mathematical (in)ability these days that those of my faculties that dealt with maths have simply deteriorated through utter disuse. In the field I'm working on, all but the most basic of maths is simply unnecessary and so I've had no cause to use them. I cannot do the kind of complex equations I learnt in the latter years of high school anymore. I would have to reacquaint myself with them now and do a bit of practising to get myself into that pattern of thinking again, before my abilities of earlier years return to any acceptable degree. I've even become slow in some basic maths that I used to take no time over. Simply lost that edge I once had from not keeping in touch. From British doco, brain pathways are maintained when one keeps reusing them (by practise). It's just like a sportsman needs to keep in training in order to achieve what he could before.
In my defense, I will say that it is not just me. Two of my friends have admitted to the same sometime in the last year, and I have noticed a similar effect of reduced mathematical ability in others - people I've known since math class in high school. I'm somewhat good at the particular field of work I do now, but the toll is that I'm not that good in other things I was reasonably good at before I specialised so. (Oddly enough, I'm still not that bad in some languages, even though I'm woefully out of touch, in that I can still read books/watch films in them. Or maybe merely watching and reading keeps me in practise.)
But I know that for a brief time I had to relearn some late high school level maths in order to solve a problem, and then I was able to regain my former abilities for the period that I kept in touch with it. (Since then, they've dwindled again. Sadly.) Surely, this is true of all people, various Hindu communities or people from the rest of the world.
Like they say, nothing keeps your brain young and avoids/keeps at bay the occurrence of deteriorating brain-diseases at an older age like keeping the brain in practise by, say, playing intelligence/memory games. Studies have advised this for people getting older.
But it is true in the more general case as well. What is lost through disuse (in our case, caused by christoBritish or islamic invasions) is something that can be regained. Centuries of disruption may take some time/some generations to completely rebuild though.
It also explains how come the amazing S American capacity for urban-civilisation building is not reflected in their present IQ. They have been reduced to outsiders living in the outskirts of their own country, they have been deprived of the knowledge that used to be passed down from generation-to-generation in their ancestors' times. Therefore, their present IQ is not indicative of what they could be capable of again if they retrain themselves.
<b>ADDED:</b>
My grandfather's free time was devoted entirely to teaching all the children in the village our languages, sciences and of course math. These kids included all the Hindu communities in the village (included kids of Harijan communities :missionary-gasp).
According to my dad, the kids were all very adept and everyone excelled when they went to college (my grandfather always kept track of his students' accomplishments and it was a matter of great pleasure for him to tell us that not a single one of his students had ever failed a subject - his Gurudakshina).
But what do my grandfather and dad know really. They were only dark S Indian Hindoos.