Evolution of Tsahaylu

[Human No More]

It certainly isn't one way, remember Jake bonding with the Pa'li for the first time?

I'd agree with the Na'vi being mentally more developed.sophisticated, although of course, there is still an element of chouce in it on the side of the animal, for example which ikran chooses a Na'vi or if they can become Toruk Makto.

for Jake and Neytiri, I don't think it would copy ALL memories to the other (or all sorts of other things would have happened differently, Jake and Neytiri would have become fluent in each other's language for one. I'd say it's more who they are than just memories (although memories would be part of it, they wouldn't be it all, or all memories) - their feelings, personality, way of thinking, as well as physical senses