36 records · three evidence periods · one bounded question
Not whether young people became smarter or less capable. This study asks what observable prose and surviving institutions reveal—under tasks that changed dramatically.
Every period contains writers coordinating ideas, causes, qualifications, evidence, and intelligible structure. The largest defensible change is in task demands and what assessments make visible: from source-free narrative, through varied short rhetorical situations, to sustained source-based analysis and argument.
The authenticated teacher-feedback result
The corpus has institutional scores, twelve current agency annotations, four aggregate editorial or unknown-marker ratings, and five later textbook-author framings. None is relabeled as teacher feedback. This is a finding about authenticated survival—not evidence that teachers did not comment. See the feedback-role ledger.
The target years were roughly 1926, 1976, and 2026. The surviving evidence is from 1919/1928, 1979, and 2024–2025. Those are the dates shown everywhere.
14 records · 5 in the calibrated core
1919
/ 1928
Five timed Virginia narratives bracket a reported 1919 median. Nine 1928 textbook pieces broaden form coverage but do not share that calibration.
Enter the 1919 / 1928 evidence →10 records · five timed tasks
1979
Age-17 NAEP responses move among description, fiction, humor, persuasion, and practical explanation. Score constructs change with the task.
Enter the 1979 evidence →12 operational anchors · three states
2024
–2025
Current writers make abstract and textual reasoning visible. Agency notes repeatedly ask for a stronger link between quotation and claim.
Enter the current evidence →What survives careful comparison
Concrete contingency and means–end thought appear in the historical material; practical and rhetorical adaptation appears in 1979; current prompts expose literary, environmental, social, and institutional abstraction. Broader visible operations do not measure “deeper minds.”
Writers qualify and consider alternatives in every period where prompts permit. Current citation is far more visible because current tasks supply and require sources. Formal rebuttal follows explicit rubric demands.
Chronology, problem–response, and claim–reason structures precede today’s thesis/body/conclusion templates. Errors coexist with recoverable conceptual structure throughout; medium, time, selection, and conventions-score skew prevent an error-rate trend.
The visible limit shifts with the assignment: unexamined causal assumptions in concrete narrative, brief support in short rhetorical tasks, and underexplained warrants in source-based essays.