Earlier quoted context omitted.
The other problem with IQ is that it's not a fixed scale, so you can't really compare IQ scores across time. An IQ of 100 is average by definition. Even if the average "intelligence" (or whatever IQ measures, because it doesn't seem to be intelligence as people think of intelligence) rises or falls over time, that average will always be a 100 IQ.
why couldn't you? i've always imagined IQ as the raw potential? or am I misunderstanding
So, to compare 100 IQ now with 100 IQ 50 years ago is hard, since you're not using the same test anymore.
There's an effect called the Flynn Effect which is essentially an inflation of IQ, so the tests are changed every few years so that it keeps the same distribution (so that the averagely intelligent human would score 100)
https://en.wikipedia.org/wiki/Flynn_effect
In fact, you can't always compare the IQ tests of 2 humans alive, because the given score is comparing you to the other people of your age, not to the global population. So if you compare the IQ of a kid and middle aged man, it doesn't mean that one is more smart than the other in an absolute way (it's more a theoretical potential)