Suppose you don't deliberately study "raw intelligence" but are interested in autism. There are a bunch of genes related to the manifestations of autism. You have a relatively low-functioning empathy circuit, for example. You develop obsessions with numbers, for example. This could be a malfunctioning orbitofrontal circuit (which is also dysfunctional in OCD patients).
It is not a coincidence that some people with superior memories exhibit very similar symptoms as autists, but retain most of their social ability, and there you go, innate, genetic intelligence, almost as a side effect of an impartially developed disorder.
What's the benefit of researching Viagra outside of pleasure? It was an accidental discover during heart research (IIRC).
You don't even have to be curious about discovering what genes are responsible for "superior" mental functions. That's almost like trying to solve a puzzle with the expectation that you only connect the pieces that you consciously set out to connect.
I've heard this objection before and I often wonder if the people making this argument secretly think that some races really are inferior, but that we mustn't talk about it.
Or, perhaps you are implying that such research might overturn our egalitarian, meritocratic society. Personally I have no fear about that. It's obvious that some people are born superstars in pure physical ability, and yet we all still enjoy sports and not all physical work has been dominated by one race.
And I think you can see that there would be huge benefits in learning what the non-genetic factors of intelligence are.
I've heard this objection before and I often wonder if the people making this argument secretly think that some races really are inferior, but that we mustn't talk about it."
Perhaps you should wonder if they're being sarcastic.
1) What's the benefit of doing this research outside of curiosity? Education research is useful, yes, but studying raw intelligence to try to figure out what parts of it are genetic seems like a waste of time, unless you plan to give babies the "smart gene" in a Sci-Fi scenario.
2) I'm not sure why you're bringing up the Italian example. It shows that Italians were performing really low, but when their culture changed, the problem went away. So, it wasn't genetic. To show something comparable about the IQ gap for black people would be really hard, because Africa is poor as hell, which depresses IQ scores, and Africans living in the First World aren't a part of the majority cultures. So, you'd either have to get all black people to be rich for a generation or have them all look white somehow but keep living in a white culture in order to make a fair comparison. It's not a repeatable experiment.