I can’t claim much about what people thought or did in their daily lives before the advent of written history but I do know that we still experience all of the same thoughts, feelings, vices, worries, failings and dreams that anyone who has ever kept a written record has throughout history. Our wider scale dealings and political intrigues are largely the same although dealing with different natural or technological events, the ones regarding interpersonal or strictly human matters are practically identical though.

You say that agriculture, writing and democracy have changed human nature but I argue they have only changed the backdrop against which the play takes place, the players and the lines are the same as ever. People didn’t think any differently when they were hunter gatherers, illiterate and living in a family group instead of a city. The subject matter would differ but the nature of the thoughts would be the same as if you were thinking about the same things.