What Shapes Children, 1900–2025

Reading the chart

Stacked areas sum to 100% per period. The calibrated version applies three defensible adjustments to the original chart's underlying logic: (1) W values tuned within literature ranges, (2) a peer/algorithm split rule that allocates 30% of algorithmic exposure to peer-mediated content, (3) reallocation of parental religious instruction to the Church channel — treating religious tradition as the formative agent and the family as its bearer.

What to trust and what to qualify

• Post-1965 cells are anchored in real time-use data (Bianchi, Hofferth, Robinson, ATUS, Nielsen, Kaiser, Pew, Common Sense Media, Gallup).
• Pre-1965 cells are reconstructions from adjacent proxies (school enrollment, female labor-force participation, broadcast penetration, religious affiliation). Treat with ±5 to ±10 point error bars.
• The original chart's pre-1980 Peers ≈ 0 is empirically implausible (kids had siblings, neighbors, classmates) — the calibrated version puts pre-1980 peer influence at ~7–14%.
• The original chart's modern Parents value may be too low; the calibrated version keeps parents at 15–21% through 2025 rather than collapsing to 10%.