Useful admonitions in this article on scale invariance in the brain. The nub of it is:

[T]he brain lacks a privileged scale because its functioning cannot be reduced to component parts (i.e., neurons).  Rather, it is the complex interactions between parts which give rise to phenomena at all spatial and temporal scales...  Like averages, reductionism is deeply ingrained in our scientific thinking.  Water is explained in terms of molecules, molecules in terms of atoms, etc.  If the brain is reducible to simpler parts, it should also exhibit a privileged scale of organization.

I suspect this could also militate against certain recommendation systems dependent on summarizing units of content, as opposed to understanding the relationships between and amongst them. We certainly see power law distributions of units of content itself, cf The Black Swan, and they may even be getting more extreme in the attention economy, or access economy as Alex Danco describes it. I’m not sure how to identify power law distributions within a novel, say, but I do know that any methodologies we might have for summarizing around scale with any level of automation as very poor. (Nonfiction, on the other hand, can be readily subjected to scale variance.)

The Alex Danco piece on Taylor Swift et al. I’m going to try to write about soon.