Notes
This book gives general information about an everyday habit. It isn't psychological advice, and it's no substitute for a GP or a therapist who knows you. The NHS guidance I mention is for England as I found it in September 2026.
I've kept sources out of the chapters where I could so they read easily. Here they are by chapter, with the limits I'm aware of. Unless I say otherwise, I read the published summary of each paper and not the full text. I checked each paper for a retraction or correction notice in September 2026 and found none. Where a chapter isn't listed, it rests on my own reasoning. That includes chapters 1, 2, 9, 12, 16, 17, 19, 20, 25 and 26. The doorway, the email, the meeting, the restaurant and Dev are invented.
Before you start. The helpline number is from the NHS pages on getting help for domestic abuse. The two-week guide for low mood is from the NHS pages on depression, both as verified for earlier books in this series.
Chapter 3. Chaudhry and Loewenstein, "Thanking, apologizing, bragging, and blaming: responsibility exchange theory and the currency of communication", Psychological Review 126, 2019, pages 313 to 344. A theory with two experiments. The extension from the theory to forty sorries a day is mine.
Chapter 4. Schumann and Ross, "Why women apologize more than men: gender differences in thresholds for perceiving offensive behavior", Psychological Science 21, 2010, pages 1649 to 1655. A diary study and a second study with imagined and recalled offences. The chapter uses the mechanism and chapter 15 returns to the gender finding with its limits.
Chapter 5. Brooks, Dai and Schweitzer, "I'm sorry about the rain! Superfluous apologies demonstrate empathic concern and increase trust", Social Psychological and Personality Science, 2013. Four studies, mostly with strangers, which the chapter says. Presented as honest counter-evidence, with the distinction between once and forty times being mine.
Chapter 6. The earlier book on not asking for help is Could you hold the ladder. The account of what the softener tells the listener is mine.
Chapter 7. Okimoto, Wenzel and Hedrick, "Refusing to apologize can have psychological benefits (and we issue no mea culpa for this research finding)", European Journal of Social Psychology, 2012. Two studies. Presented as a caution about the opposite habit and not as a recommendation.
Chapter 8. Lewicki, Polin and Lount, "An exploration of the structure of effective apologies", Negotiation and Conflict Management Research 9, 2016. Two studies with scenarios. The six components are theirs. The claim that the reflex sorry devalues the real one is mine.
Chapter 10. Savitsky, Epley and Gilovich, "Do others judge us as harshly as we think? Overestimating the impact of our failures on others' judgments", Journal of Personality and Social Psychology 81, 2001, pages 44 to 56, as verified for the earlier book Say no. What people think of "thanks for waiting" is my observation.
Chapter 11. Kim, Ferrin, Cooper and Dirks, "Removing the shadow of suspicion: the effects of apology versus denial for repairing competence- versus integrity-based trust violations", Journal of Applied Psychology 89, 2004, pages 104 to 118. Workplace scenarios. The chapter uses only the point that an apology implies a violation. Chaudhry and Loewenstein as above, for thanking.
Chapter 13. Kim and colleagues, and Savitsky and colleagues, as cited below and above. The observation that the anger rarely arrives is mine.
Chapter 14. The NHS page "Raising low self-esteem", for the origins in childhood messages and the method of noting negative thoughts and writing evidence against them.
Chapter 15. Schumann and Ross as above. The chapter makes no claim about gender beyond that study's finding about thresholds.
Chapter 18. The NHS page as above, for avoidance reinforcing doubt. Chaudhry and Loewenstein as above. The earlier book on self-criticism is You wouldn't say it to a friend. The rest is mine.
Chapter 19. The earlier book on saying yes to everything is Say no. Everything else in the chapter is my reasoning.
Chapter 21. Chaudhry and Loewenstein as above, for thanking as the communication that gives credit without taking blame. Brooks and colleagues as above. The earlier book on lateness is Sorry I'm late.
Chapter 22. Lewicki and colleagues as above. The choice of three components is mine. The earlier book on lateness as above.
Chapter 23. Gollwitzer and Sheeran, "Implementation intentions and goal achievement: a meta-analysis of effects and processes", Advances in Experimental Social Psychology 38, 2006, pages 69 to 119. The rule hasn't been tested as a package, and what I say to expect is my expectation and not a finding.
Chapter 24. The helpline and the NHS pages as above. The earlier book on being interrupted is Let them finish.