NB: Originally published on Map and Territory on Medium. This is an old post originally published on 2016-09-10. It was never previously cross-posted or linked on LessWrong, so I'm adding it now for posterity. It's old enough that I can no longer confidently endorse it, and I won't bother trying to defend it if you find something wrong, but it might still be interesting.

I find Kegan’s model of psychological development extremely useful. Some folks I know disagree on various grounds. These are some accumulated responses to critiques I’ve encountered.

Before we dive into these critiques, though, allow me to attempt a brief introduction to the theory (though this is a tough undertaking, as we’ll discuss below). Robert Kegan, later along with Lisa Lahey, put forward a theory of developmental psychology rooted in complexity of meaning making. It is influenced and builds on the work of Piaget, but also Erikson and Kohlberg, who extended developmental psychology to consider the possibility of adult development.

Kegan’s theory focuses on the maximally complex models people can make of the world in near construal mode. Development is along a continuous gradient but with clear “levels” where a particular kind of complexity is fully available to the thinker. These are classified from 1 to 5 and can be summarized in many ways, though fundamentally they correspond to when a person can form fully-articulable models of things, relationships between things, systems, relationships between systems, and systems of systems (holons), respectively.

This is an exceedingly dense introduction, though, and I know of no good short explanation. The best resources on the topic remain Kegan’s seminal The Evolving Self and his later In Over Our Heads for a more approachable, example-laden presentation.

The first, and perhaps strongest, critique of Kegan is that it’s very hard for anyone to explain it. Kegan begins In Over Our Heads with the story of getting a letter from a student assigned to read The Evolving Self. The student writes that The Evolving Self is full of interesting ideas but gets so frustrated trying to make sense of it that he wants to “punch [Kegan] in the teeth”.

Partly this is because of Kegan has a strong literary and classics background, so The Evolving Self is full of very precise languag...