@Comment 29 by phil rimmer

mode(s) of learning

Fascinating. Twin braids of instruction, culturally/traditionally segregated by gender, suggesting indeed distinct types of meme as per SC (Comment 28), with differing requirements for successful transmission.

The "intention" memes, SC's meme2, would be subject to greater variation, I suppose, while the "action" memes would need to be copied with greater fidelity, though still not always 100%, as mutations (mis-rememberings, or wilful tweaks) give rise to variations.

Or rather, the "intention" memes are not instructions on exactly-what-to-do, but instructions on how to go about figuring out what to do, which can then be useful in as-yet-unknown situations. Perhaps they copy just as faithfully as "action" memes, though they appear more able to pick up new material.

As for the earlier discussion on mental states and how "exact" must be the copy for memes to work, the answer seems to be: nowhere near exact.

Even a software application these days can identify a tune, despite differences in noise, pitch, rhythm, instrumentation/timbre, recording quality, sample rate, compression algorithms. So there is no need for brain-to-brain reproduction of exact neural or mental states, only for "enough" of an idea to be transferred to count as replication of a meme, as determined by observable behavior.

And that was just on the simple end of the scale, a tune. On the complex web of mutually supporting concepts and habits that comprise a religion, the mental states involved can differ wildly, all that matters for meme propagation is that "enough" of the essentials are passed along.

Indeed, the successful long lived "meme" contains mechanisms to counter the potentially high mutation rate. Long lived folk or ethnic music has strong internal structure that survives different interpretations in playing. It was only with the invention of written musical notation that entire complex arrangements could be composed that would outlive the composer and those he'd personally conducted.

Religions, seen as "memes", contain a variety of checks-and-balances to ensure that the meme propagates unchanged. The RCC ensures this by control of teaching and tradition. Reciting a creed helps remind the faithful what it is they're supposed to believe, and trained habit gets them to do this on a regular basis.

Book-based religions do it by holding central an immutable "database" of material, though even then sub-species (schisms) arise by point mutation - a single influential teacher can spawn a whole new sect.