direct response to anecdote and then back to response

That was the structure your post used! ...which was an awesome example of a coherent meshing of form and content, where the claims were consistent with the exhibited behavior.

From my mid-twenties to my early thirties while writing in online discussion forums I've noticed something like content-behavior coherence increasing but I've never really thought about it explicitly or hypothesized mechanisms.

My impression is that my writing has increased in quality but decreased in flexibility? If I've determined for myself the correct answer to something based on previously existing evidence I'm likely to be acting in a manner consistent with my beliefs and can simply re-verify the state of evidence on the subject and its connection to my conclusions and then (assuming the answer hasn't changed) repeat the earlier sentiment with more attention to communication. The content-behavior coherence might fall out of this, but I still struggle with verbosity...

Hey! This suggests an improvement strategy: find a forum for writers talking about the craft of writing, and experiment with asking questions and later with giving advice about writing until I can offer good advice that has "behavior-content coherence" :-)