Ive never looked into a test by a Sri Lankan or any specific group.
But, there are some tests that include comprehension and vocabulary. Some lanuage aspects. But, I'd argue that kind of test can be very culturally determined as not all languages are the same.
Also, I've never said its the only indicator of intelligence. I've just said it's a reasonably accurate one based on correlation studies. That was my main point. One big problem with IQ tests, I will admit, is that they dont measure potential or educability of someone. This is more so a problem with younger people taking them.
Genetics plays a major role. But me mentioning the upper classes of those countries was due to the fact that they have much more access to education than the lower classes. Not to say that it's all genetics or all education. India for example, has a caste system and some distinct groups of people in the country. So, you can make an argument on a genetic and an environment case.
If you don't mind me asking, what country are you from? And do you know which specific test you took?