What Developmental Milestones Are You Missing?

A speculative essay (Scott flags it as condescending/elitist) extending developmental psychology to adults. After reviewing childhood stages (theory of mind via the Skittles/pennies false-belief test, magical thinking, self-environment boundaries) and the dubious 'primitive cultures show less formal-operational thought' claim, it runs with David Chapman/Robert Kegan's idea that <half of modern Western adults reach Kegan's 4th stage. The generative move: many 'developmental milestones' may be learned mental operations, not innate unfoldings — e.g. General Semantics' 'map is not territory' is theory-of-mind some adults lack; Nathan Robinson 'gets the thing' (others go down as many levels to defend their values as you do). Lists candidate adult milestones (distinguishing brain-output from reality [CBT], modeling other mind-designs, probabilistic thinking, understanding trade-offs); both psychotherapy and LW-rationality teach these, and the Sequences' alien-mind training may double as an anti-egocentrism hack.

Quality 74 · Strong. Strong, upper. A genuinely generative, memorable reframe (adult cognitive development / 'what mental operations are you missing / lacking the socket the piece snaps into') with sharp examples (map-is-not-territory-as-theory-of-mind, 'gets the thing,' the trade-offs milestone). Held at top-Strong by its explicit speculativeness, its reliance on the not-well-validated Kegan stages, and the dated/uncomfortable 'primitive cultures = child stages' anthropology.

Claude’s paradigm shift 55 · Moderate. Moderate–Notable (55). The 'adult developmental milestones / some adults lack basic mental operations' synthesis was a fresh, generative reframe, building on borrowed Chapman/Kegan scaffolding.

Real-world impact 2 · Minor. Minor (2). The 'missing-mental-operations / missing the socket' frame circulates in rationalist discourse; no material-world reach, and the scaffolding is borrowed.