>But all intelligence, of any sort, is "jagged" when measured against a different set of problems or environments.
On the other hand, research on "common intelligence" AFAIK shows that most measures of different types of intelligence have a very high correlation and some (apologies, I don't know the literature) have posited that we should think about some "general common intelligence" to understand this.
The surprising thing about AI so far is how much more jagged it is wrt to human intelligence
I think you are talking about correlation in humans of, say, verbal and mathematical intelligence. Still, it is a correlation, not equality - there are many word-acknowledged writers who suck at math, and mathematical prodigies who are are not the best at writing.
If you go beyond human species (and well, computers are not even living organisms), it gets tricky. Adaptability (which is arguably a broader concept than intelligence) is very different for, say octopodes, corvids and slime molds.
It is certainly not a single line of proficiency or progress. Things look like lines only if we zoom a lot.
Human intelligence has had hundreds of thousands of years of evolution that removes any 'fatal' variance from our intelligence. Too dumb is obvious on how it's culled, but 'too smart' can get culled by social creatures too, really 'too different' in any way.
Current AI is in its infancy and we're just throwing data at it in the same way evolution throws random change at our DNA and sees what sticks.
On the other hand, research on "common intelligence" AFAIK shows that most measures of different types of intelligence have a very high correlation and some (apologies, I don't know the literature) have posited that we should think about some "general common intelligence" to understand this.
The surprising thing about AI so far is how much more jagged it is wrt to human intelligence