I wonder if there were companies that instead of growing as a single entity created early spin-offs to diversify aside without losing the core spirit. It's so common to see success become bloated and resist death by all commercial means necessary while newcomers bring something fresh to the table.
I've wondered for a long time if that's exactly why George Lucas intentionally created separate companies while he made all his movies (e.g. ILM, Lucasfilm, LucasArts, THX, Pixar). I wonder if there's either a good book that goes into detail about that, or if anyone on HN knows him close enough to ask him directly. :-)
Dunbar's number is interesting. His methods were not particularly scientific but his language was. It was a fairly formative paper for me when i was studying history of science.
I do think there is something in the number, but where it comes from is unclear.