Notes

Every substantive claim in this project is anchored to named, published research or to documented public record. Sources are listed below by chapter and keyed to the phrase they support, so any claim can be traced and checked independently. Where a finding is contested in the literature, that is stated in the text rather than left to the notes — the honest state of this field is that some of it is settled and some of it is not.

Chapter 1 — The Depth Deficit

"researchers at the MIT Media Lab wired fifty-four people" — Kosmyna, N., et al. (2025). “Your Brain on ChatGPT: Accumulation of Cognitive Debt when Using an AI Assistant for Essay Writing Task.” MIT Media Lab, arXiv preprint.

"measurably enlarged posterior hippocampi" — Maguire, E. A., et al. (2000). “Navigation-related structural change in the hippocampi of taxi drivers.” Proceedings of the National Academy of Sciences 97(8).

"researchers at McGill followed what happened next" — Dahmani, L., & Bohbot, V. D. (2020). “Habitual use of GPS negatively impacts spatial memory during self-guided navigation.” Scientific Reports 10.

"surveyed 319 knowledge workers about 936 real AI-assisted tasks" — Lee, H.-P., et al. (2025). “The Impact of Generative AI on Critical Thinking.” CHI 2025. Microsoft Research / Carnegie Mellon University.

"A Harvard field experiment run inside the Boston Consulting Group" — Dell’Acqua, F., et al. (2023). “Navigating the Jagged Technological Frontier.” Harvard Business School Working Paper 24-013.

"experienced endoscopists’ unassisted detection rates measurably dropped" — Budzyń, K., et al. (2025). “Endoscopist deskilling risk after exposure to artificial intelligence in colonoscopy.” The Lancet Gastroenterology & Hepatology.

Chapter 2 — The Taste Economy

"the consultants who did best with GPT-4" — Dell’Acqua, F., et al. (2023), ibid.

"Anders Ericsson’s decades of work on how elite performers actually form" — Ericsson, K. A., Krampe, R. T., & Tesch-Römer, C. (1993). “The role of deliberate practice in the acquisition of expert performance.” Psychological Review 100(3).

Chapter 3 — The Attention Recession

"the average worker held attention on one screen for about two and a half minutes" — Mark, G. (2023). Attention Span. Hanover Square Press.

"workers took on the order of twenty-three minutes to fully return" — Mark, G., Gudith, D., & Klocke, U. (2008). “The Cost of Interrupted Work.” CHI 2008.

Chapter 4 — The Patience Dividend

"For forty-two years, I’ve been making small, regular deposits" — Sullenberger, C., interview following US Airways Flight 1549, 2009; see also Sullenberger, Highest Duty (2009).

"on the order of a decade of deliberate practice" — Ericsson et al. (1993), ibid.

Chapter 5 — The Friction Premium

"reconstructed in the French accident bureau’s final report" — Bureau d’Enquêtes et d’Analyses (2012). Final Report: Air France Flight AF 447.

"a now-famous lecture titled ‘Children of the Magenta Line’" — Vanderburgh, W., American Airlines Flight Academy training lecture, 1997.

"issuing a formal safety alert urging airlines" — FAA Safety Alert for Operators (SAFO) 13002 (2013).

"the psychologist Robert Bjork spent a career documenting" — Bjork, R. A. (1994). “Memory and metamemory considerations in the training of human beings.”

"Henry Roediger and Jeffrey Karpicke showed" — Roediger, H. L., & Karpicke, J. D. (2006). “Test-Enhanced Learning.” Psychological Science 17(3).

Chapter 6 — The Originality Problem

"an elegant experiment published in Science Advances" — Doshi, A. R., & Hauser, O. P. (2024). “Generative AI enhances individual creativity but reduces the collective diversity of novel content.” Science Advances 10.

Chapter 7 — The Mentorship Gap

"Ericsson’s work identifies as the coach’s central function" — Ericsson et al. (1993), ibid.; see also Ericsson & Pool, Peak (2016).

Chapter 8 — The Presence Premium

"roughly thirty-four times more effective" — Roghanizad, M. M., & Bohns, V. K. (2017). “Ask in person.” Journal of Experimental Social Psychology 69.

Chapter 13 — The Parent & the Home

"three MIT researchers published an experiment in Science" — Leonard, J. A., Lee, Y., & Schulz, L. E. (2017). “Infants make more attempts to achieve a goal when they see adults persist.” Science 357(6357).

Chapter 10 — The Knowledge Professional

"Judge P. Kevin Castel asked a lawyer named Steven Schwartz" — Mata v. Avianca, Inc., No. 22-cv-1461 (S.D.N.Y. 2023).

"developers completing a standard task fifty-six percent faster" — Peng, S., et al. (2023). “The Impact of AI on Developer Productivity: Evidence from GitHub Copilot.”

Chapter 10 — The Healthcare Professional

"a study that gave the depth deficit its first hard clinical number" — Budzyń, K., et al. (2025), ibid.

Chapter 11 — The Educator

"a team of Wharton researchers led by Hamsa Bastani" — Bastani, H., et al. (2024). “Generative AI Can Harm Learning.” Wharton School / SSRN working paper.

"Roediger and Karpicke’s retrieval-practice research" — Roediger & Karpicke (2006), ibid.

Chapters 14–17 — The Formula

"the MIT essay-writers skipped" — Kosmyna et al. (2025), ibid.

"Gloria Mark’s forty-seven seconds" — Mark, G. (2023), ibid.

Chapter 16 — The Depth Deficit Index

"as phrased by Marilyn Strathern" — Strathern, M. (1997). “‘Improving ratings’: audit in the British University system.” European Review 5(3).

"a meta-analysis of more than a hundred studies led by Benjamin Harkin" — Harkin, B., et al. (2016). “Does Monitoring Goal Progress Promote Goal Attainment?” Psychological Bulletin 142(2).

Chapter 17 — The Counter-Movement

"Bloomberg’s report on it quoted his reasoning" — Trudell, C., & Hagiwara, Y. (2014). “‘Gods’ Edging Out Robots at Toyota Facility.” Bloomberg News.

"Researchers who later analyzed tens of thousands of professional moves" — Choi, S., et al. (2023). “How Does Artificial Intelligence Improve Human Decision-Making?” Working paper.