People have been implementing laws and punishments since at least 2060 BC Ur-Nammu, which is a code of laws, composed of "if, then" statements or laws is an indicator that awareness of the concept of responsibility dates back 4000 years. There is also a great probability that there were other legal codes like this, and many other verbals, even older than Ur-Nammu. It shows that even at that time people held each other accountable for their actions and didn't think that somehow it wasn't their fault. This leads me to think that people have never "invented" the concept of free will, but have already had it since birth