Could nonhuman great apes also have cultural evolutionary psychology?

Attempted answers are given to (a) whether nonhuman great apes (apes) also have evolved imitation (answer: no); (b) whether humans can transmit imitation as a gadget to apes (answer: yes, partly); (c) whether human-to-ape transmission can kickstart subsequent and stable ape cultural evolutionary psychology ("CEP"; answer: unlikely); and (d) when CEP evolved in our lineage (answer: relatively late).