Just getting the first comment in for what will be a funwild ride. Keep it going, Mr. Bacon.
Neat ideas well executed. Unfortunately you have hitched your theory of mental evolution to the least credible part of natural selection- the idea that frameshift mutations are sometimes pro-survival. There simply don't seem to be any examples of this and I've looked quite a bit for them. Random mutation has never been demonstrated to enhance the offspring, which is why after almost two hundred years evolution remains a thing that we believe in because experts say so and not a thing that anybody ever demonstrates or measures.
The announcement this week that the FDA has given the go ahead to the development of a canine longevity drug makes me feel like we might have been domesticated by dogs rather than our own culture.
So play? Childlike (serious play) > Neanderthal?