That may be inaccurate regarding the same cognitive development as cavemen. Modern man may have developed a more sophisticated prefrontal cortex over time, which is the area of reasoning and logic.
If by 'cavemen' you mean something like Neanderthal, then there may well be substantive differences in cognitive equipment between them and us. But if you mean cave
men, i.e., early humans, then there can't be much difference, because by definition we've got the same genes as them (being the same species and all), and genes determine traits. Additionally, 100k years is a blink of an eye in evolutionary terms and, given that it tends to work very gradually, there are almost certainly no significant differences between us and the earliest humans.
Also, in my original post I said cognitive "equipment," not cognitive "development." Perhaps we've reached a higher level of cognitive development due to non-evolutionary factors like better nutrition and higher living standards, but it's still true that this is being eked out of the very same "equipment," or mental machinery, that the cavemen had.
So really, we're cavemen who are squeezing a bit more performance out of our brains than our old friends were able to, not fundamentally different beings than they.