- They are able to stand on the shoulders of a far broader range of giants, thanks to writing; and

- They have access to far more tools of reasoning (arithmetic with Roman numerals is just the start!) that those in the past did not have.

So while there may well have been intellectual equals to the geniuses of today also back then, they would not have been able to perform the feats of geniuses today. Again, for lack of tooling, not wit.

Arabic, I think you mean. Arithmetic with Roman numerals is awful.

Hindu numerals, do you mean?

https://en.wikipedia.org/wiki/History_of_the_Hindu%E2%80%93A...

and be sure to knock them in the head (and everyone that you want to bring with them) so they won't remember anything. I doubt they are any different than a hairless monkey. One thing that we got going for us is the written/oral knowledge that we have accumulated.

A George Carlin quote comes to mind:

Think of how stupid the average person is and then realize that half of them are stupider than that.

What makes you think this is true? I have plenty of experience of people who play very nicely with each other, even when they are for all practical purposes not bound by law to.

> why it took us a hundred thousand years to escape a subsistence lifestyle

You use the word "escape" as though we are universally better off now than when we spent a few hours a day foraging. Do you have evidence for this? What if people preferred to live their lives the way they did -- much like, I suppose, you prefer to live life the way you do?

(No doubt do many people now have it better than many people then, but it sounds like you're asserting that the opposite is not the case too.)