Crux of your argument is:
Considering that the above happens, the question is why do people have such biases?
The important thing to note here is that biases of caste, religion, region, party-loyalty, etc comes from taught behaviour and not hereditary behaviour.
Your argument is related with the '
social awareness' which I believe has little to do with the democracy, nevertheless, let me put my final thoughts:
If government starts intruding in people's personal spaces/freedom or starts behavior-modification-in-grand-ways; it is called
dictatorship!! China can force 1 child-policy, Indian Govt can NOT.
Not many countries (democratic or not) discriminate on the basis of caste (SC candidate gets a job despite being lower in ranking than general candidate), you implement the same rule in India (i.e.,
abolish caste-based-reservation or govt-sanctioned-caste-system, in a way)-- there will be total anarchy!
'Shah Bhano case' happened in India (however adverse it might be to the rights of women) because the Muslim at large in India
wanted their personal lives to be a guided by their religion. Apparently Indian muslims rallied for this!!
Indian Govt (or democracy) does
NOT preach marriages
only in "same-caste",
our parents do!! Govt had legalize inter-caste marriages
decades ago, how many parents are comfortable with such marriages
even today? Govt can, at best, provide the legal protection to couple who fear for their lives from their parents.
Govt already did what it could i.e., to tell people that "inter-caste marriage are OK, republic children. Please go ahead with these."
What else you think that govt should do to
eliminate the caste-biases prevailing in our society??
Govt can only advertise 'Save the Girl Child' to create awareness among people BUT can it go to every house to check if "gender equality" principle is adhered in totality by all parents? No, it can not.. it is impossible.
It can facilitates the awareness up to some extent beyond that
any major social change HAS to come from within the society.
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Reg your question of behavior modification while abroad:
First of all, numbers of people going abroad is very very less (i.e., it is bad sample -size and -choice). I have been to Singapore and have also spent a considerable amount of time in Europe (Barcelona to be specific). I did NOT change my behavior in Barcelona or in Singapore in any significant way. I was as
"free" in Barcelona as I am in Bangalore.
I think you'r observations are reg the Singapore's rule of 'littering' things around, smoking in public places and probably the yellow line rule (while road-crossing). [
It is more of question of the resources at the govt disposal.]
Well, I don't throw trash on the road in Bangalore either; I always use dust-bins;
So, as a corollary question
: Why didn't the bad-governance-system-in-India encourage (!) or modify my behavior to throw trash around?? Is it hereditary?
BTW, stark behavior modification (!) while abroad is seen among the people who travel to middle-east countries (pious Islamic nations)!!

and Lo! most of them are not even democracy?
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Another counter argument I can think of: Sometime back there were news of honor killings in NRIs (in UK). Well, the governance is same for the NRIs and Britons;
why do then some NRIs have "these" biases?? (If these are indeed taught or result from the bad- governance)
I am not able to find it but sometime back I read one article with the statistics of inter-racial marriages in UK. Even the 2nd and 3rd generation Indian (most South Asians for that matter) migrants do not prefer inter racial marriages!! Most importantly, a white girl is more likely to get married to a black dude as compared to chances of brown girl being married to a black dude.
Kindly explain since when UK govt started
teaching such biases/ prejudices?
(Anyway I don't see how it is related with the concept of democracy!)
Let me put it again:
Social changes always manifest in bottom-to-top approach/manner. If govts try social change in a top-to-bottom approach: either it
fails OR people change the govt and then it
FAILs.