CONCEPT
Delayed Developmental Milestones
The longitudinal pattern in Twenge's data showing that successive American generations achieve driver's licenses, first jobs, romantic relationships, and financial independence at later ages — the empirical signature of the slow life strategy operating across cohorts.
Delayed developmental milestones is the empirical pattern Twenge has documented across five decades of nationally representative surveys. Specific findings: driver's license holding among high school seniors fell from 92% in 1976 to 71% by 2014 and has continued falling since. Part-time employment during high school has declined similarly. Age of first romantic relationship, first sexual experience, first independent living, and first full-time employment have all shifted later across successive cohorts. The pattern is not explained by economic conditions alone — it persists across socioeconomic strata and through periods of both prosperity and recession. It is the empirical signature of the slow life strategy and the ground-level evidence for the argument that iGen enters the AI era with less experience of independent functioning than any prior American generation.
In The You On AI Field Guide
The delayed milestones data matters because each milestone represents a specific developmental experience. Obtaining a driver's license is not merely a