Why Self-Help groups are CoPs
Etienne Wenger and Jane Lave include a group of Alcoholic Anonymous among their examples of CoPs in their 1991 book Situated Learning. But, they never explained how so, or verified such hypothesis aside from noticing some suggestive and striking comparisons between practice in CoPs and practice in an AA group.
The key of such comparison is the fact that, if social interaction shapes the sense of self as Vygotsky claims, then one of the main functions story-telling accomplishes in CoPs is identity formation (the other one being: allowing implicit-to-implicit knowledge flow and sharing).
Just recently, the Scottish Recovery Network started a research project on storytelling, unravelling details on how story-telling reshapes the self. I'm anxious to see the rest of this work!