Everytime the Tamil enthusiasts strut forward with theories on the hoary culture, the antiquity, the richness etc they are often faced with a glum sceptic public who just say "good, so what, lets talk about the present". Then we are forced to listen to hypothesis on how learning in mother-tongue accelerates learning, gives better understanding and finally makes a student a better student than learning in an alien tongue. Its time to question the premise and the hypothesis that flows out.
The first premise is that when children learn in the same language that is spoken at home they can understand what is taught very readily thus grasping it effectively. What is reality? Tamil has an unfortunate dichotomy between the colloqial version (spoken at home) versus not just literary Tamil but even what is used in plain textbooks. I still remember my first Biology class at Don Bosco very vividly. Brother Deva who taught it began by saying "bios means life and logos is 'study' therefore biology is study of life". Now think of a Tamil class. Yes the Tamil word "uyiriyal" (actually that is only an equivalent of zoology) is good, consider 'thavara iyal' (Botany). I can bet my farm that no home, irrespective of how well educated, uses the word "thavaram" to denote plants, colloqially we call it "chedi". This is just one instance.
My wife studied in Tamil medium completely. Out of the blue I asked her what did she study as Tamil equivalent of "matrix" (in math). She had to think hard and fish out the word "ani". Not a great equivalent. The point is learning in mother tongue did not make it easy to grasp the word because the word used is not what is in daily use. Matrix, on the other hand is used daily. Also if one were to see other usages like "matrix reasoning" we find that Tamil falters. Many mathematical terms are like that, the Tamil words are so far removed from daily use words that they might as well be in Greek or Latin. "mee peru vaguthi" -- Greatest common divisor. "mee chiru perukki" -- Least Common multiple. Now consider a common slum boy or girl, their Tamil is totally different from all these terms.
Remember children enter classes at 3-4 years of age, a very malleable mind, they spend most of their waking, conscious hours at school, if these are capitalized on then they can learn in any language, even Swahili as for that matter.
Take the case of tri-lingual houses. Let's say a Telugu family. I used to have a Telugu friend, she would be talking to me in English+Tamil but would switch to Telugu seamlessly when talking to her sister who passes by. Take the case of Afro-Americans, Hispanics etc in America they all talk different languages at home and send their children to English speaking schools.
Often times the other excuse is our schools in TN are ill equipped to teach in English. Our schools are simply ill equipped to teach anything in any language. Our teachers are the most ill equipped. Its not that teachers in US are of higher IQ or more dedicated, they are just better equipped. I once worked for McGraw Hill and was amazed to see the support material McGraw provides for teachers to teach using their textbooks.
We also lack hard empirical data or statistics of learning delays in bilingual children (Erika Hoff : Learning Development). There is no comprehensive multi-year study.
If we accept this argument of teaching in the same language that is spoken at home / neighborhood it is not a far leap to then say we can only teach to students whose parents are educated in turn. Yes, its a great advantage if parents are educated but the excellence of an educational system is measured by how well it caters to an under privileged student. Language is just a medium of instruction. A student from a slum, unfortunately, encounters a whole new world at school, the ideas in each subject are alien, the culture would be alien, the demands are alien. The language factor is more a truism than a true cause.
A crucial factor that we need to remember is that understanding of how language are learnt is itself a veritable battlefield. A joke in anthropology states, "no tribe has been discovered without language". This is true of the most secluded pristine tribes in Amazon jungles. Starting with CHomsky's theory of "universal grammar" to Steven Pinker's "language instinct" many theories abound, but all conceded that children are the fastest to learn languages and can handle as many as they are exposed to .
Many classmates in my class came from very normal backgrounds, literate but very literary families. Nobody suffered from language delays as a result of studying in English. Yes, some stumbled but the advantage of our learning-by-rote system is finally they just had to memorize. This lacuna is equally true for Tamil medium. In my home and my neighborhood nobody used English. Even at school we freely used Tamil.
My wife has done extremely well in her career and now speaks pretty good English. Many Indians in USA do well with a moderate fluency in English. However anybody who did not study in English in shool had a difficult transition period in college, actually the learning delay due to THAT is more evident. Many Indians reach mid level position based on technical expertise but fail to go higher primarily due to lack of ability to articulate higher reasoning in English. The lack of fluency is worsened by the almost total lack of extra-curricular reading in English by Indians.
That we live in a world dominated by English is no secret there is no let up on that. Stop with stupid questions like in english there is only "uncle" to denote "chithappa, periappa, mama etc". Tamil will do a double take before it can label the ever exponentially expanding sub-atomic particle zoo. So let's close down the Tamil Medium schools. Conserve resources, redirect efforts to rearing a English speaking population.