Our ancestors' brains went from chimpanzee-sized to modern-sized (actually slightly bigger than today) between two million and one million years ago, and more importantly the language-governing areas increased in size during that stretch. So human beings a million years ago were very much like us today, just without the advanced technology.

Millions of years, likely. The whole reason we’re successful is because our pre-human ancestors were empathetic and cooperative enough to build societies.

We see those same traits in many other primates, and they’re not something it makes sense to evolve, lose, and evolve again. Those traits predate us.

Language almost certainly predates us, since we see it not only in other primates, but in non-primate species, too. And based on the humour we see in many animals, you can bet we were making dick jokes nearly out of the gate.

Always has been. This is where the whole "Dark Ages" idea comes from, IIRC: people further on in time wanting to separate themselves as special and more advanced.