Notes

These notes give the sources behind the claims in each chapter, and say where I'm giving my own interpretation. The book isn't medical advice. If your treat is alcohol and it's daily, or your eating feels out of control, or the day has felt empty for weeks, the preface says where to go and a GP is the person to ask. The examples throughout, the glass at six, the bar at the counter, the order on the bad Tuesday, the vape on the step, the phone in bed and the partner with the bag from the shop, are invented to illustrate and aren't drawn from real people.

Studies were checked on 26 September 2026 by reading their published abstracts. None was read in full, and none carried a retraction or correction notice at that date. Where a study is a review or a model, I've said so, and where the work was done with animals, I've said that too.

Chapter 1. No sources. The terms are the book's own.

Chapter 3. Taylor, Webb and Sheeran, "'I deserve a treat!': justifications for indulgence undermine the translation of intentions into action", British Journal of Social Psychology 53, 2014, pages 501 to 520, as used in The biscuit tin. Kivetz and Zheng, "Determinants of justification and self-control", Journal of Experimental Psychology: General 135, 2006, pages 572 to 587. Khan and Dhar, "Licensing effect in consumer choice", Journal of Marketing Research 43, 2006, pages 259 to 266. Five studies. Blanken, van de Ven and Zeelenberg, "A meta-analytic review of moral licensing", Personality and Social Psychology Bulletin 41, 2015, pages 540 to 558. 91 studies, 7,397 participants, an effect size of 0.31. The claim that the earning arrives after the decision and can't tell days apart is mine.

Chapter 4. Wood and Rünger, "Psychology of habit", Annual Review of Psychology 67, 2016, pages 289 to 314. A review. Wood, Quinn and Kashy, "Habits in everyday life: thought, emotion, and action", Journal of Personality and Social Psychology 83, 2002, pages 1281 to 1297. Two diary studies with hourly reports. The claim that a reward marks and the daily can't is mine, and so is the bell.

Chapter 5. Galak and Redden, "The properties and antecedents of hedonic decline", Annual Review of Psychology 69, 2018, pages 1 to 25. A review. Berridge, Robinson and Aldridge, "Dissecting components of reward: 'liking', 'wanting', and learning", Current Opinion in Pharmacology 9, 2009, pages 65 to 73. A review of largely animal work, and the chapter says so. That the best bit is mostly the wanting is my reading.

Chapter 6. The NHS page on alcohol units, at nhs.uk, read on 26 September 2026, for the definition of a unit, the formula, the fourteen-unit guidance, spreading over three or more days and drink-free days. The 2.3-unit figure for a 175-millilitre glass at thirteen per cent is my arithmetic using the NHS formula, and the sixteen a week follows from it. The rest of the chapter is my reasoning.

Chapter 7. Quoidbach and Dunn, "Give it up: a strategy for combating hedonic adaptation", Social Psychological and Personality Science 4, 2013, pages 563 to 568. The abstract doesn't give the number of participants. That the flat evening is the expecting unmet, and that it fades, is my extension of a one-week study.

Chapter 8. Adam and Epel, "Stress, eating and the reward system", Physiology and Behavior 91, 2007, pages 449 to 458. A review proposing a model, drawing on animal and human research, and the abstract says the human mechanisms are only starting to be understood. The earlier book referred to is The feeling will pass without help. The lid is mine.

Chapter 9. No research sources. The earlier book referred to is Cook the simple thing. The argument that the daily can't scale is mine.

Chapter 10. Kivetz and Simonson, "Earning the right to indulge: effort as a determinant of customer preferences toward frequency program rewards", Journal of Marketing Research 39, 2002, pages 155 to 170. About 3,100 consumers, studies of loyalty schemes. The reading of "punishment" is mine.

Chapter 11. Hagger and colleagues, "A multilab preregistered replication of the ego-depletion effect", Perspectives on Psychological Science 11, 2016, pages 546 to 573. 23 laboratories, 2,141 participants, an effect size of 0.04 with a confidence interval including zero. The earlier books referred to are The drink didn't do that, The next episode, The phone can wait and The biscuit tin, and the claims about sleep are theirs, not restated here.

Chapter 12. Neal, Wood, Wu and Kurlander, "The pull of the past: when do habits persist despite conflict with motives?", Personality and Social Psychology Bulletin 37, 2011, pages 1428 to 1437. Two field experiments. The parcel is mine, and so is the application to six o'clock.

Chapter 13. Goldsmith, Cho and Dhar, "When guilt begets pleasure: the positive effect of a negative emotion", Journal of Marketing Research 49, 2012, pages 872 to 881. That the guilt is a flavour, and the bedtime loop, are my readings.

Chapter 14. No research sources. The earlier books referred to are Ask the price of the evening and Put the card away. No figure for money is given because none was verified.

Chapter 15. The NHS page on five steps to mental wellbeing, at nhs.uk, read on 26 September 2026. The lid is my reading. The depression pointer is to the NHS page on symptoms of depression in adults, read the same day.

Chapter 16. Nelson and Meyvis, "Interrupted consumption: disrupting adaptation to hedonic experiences", Journal of Marketing Research 45, 2008, pages 654 to 664, as used in You didn't want it yesterday. Sheldon and Lyubomirsky, "The challenge of staying happier: testing the Hedonic Adaptation Prevention model", Personality and Social Psychology Bulletin 38, 2012, pages 670 to 680, as used in What did you expect it to fix. 481 students over three months. That three a month are better than thirty, each, is my claim and not theirs.

Chapters 17 to 20. No research sources. The three questions, the two ways out, the blank day and the proper treat are my suggestions and haven't been tested as a method.

Chapter 21. 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. Lally, van Jaarsveld, Potts and Wardle, "How are habits formed: modelling habit formation in the real world", European Journal of Social Psychology 40, 2010, pages 998 to 1009. 96 volunteers, 82 with usable data. The rule hasn't been tested and what I say to expect is my expectation, including the guess that unlearning runs on a similar clock to learning, which Lally didn't study.

Chapter 22. The NHS pages on alcohol units and on alcohol support, at nhs.uk, read on 26 September 2026, for the guidance and for the warning about stopping overnight when physically dependent. The helpline number isn't printed because numbers and hours change. The NHS eating disorders overview, read the same day, names Beat. The earlier books are named in the text. No claim is made about the effectiveness of any service.

Chapter 23. The NHS page on symptoms of depression in adults, read on 26 September 2026. The earlier books referred to are The lie-in costs more than it gives, Let them do it badly and They're nine, not lazy. Everything else in the chapter is my suggestion.

Chapter 24. Lally and colleagues, as above. The extension from a missed day to a missed evening, and from forming a habit to unlearning one, is mine.

Looked up and not used. Redden's 2008 paper on categorisation and satiation in the Journal of Consumer Research had no abstract available to me and isn't cited. Ramanathan and Williams's 2007 paper on the emotional consequences of indulgence couldn't be retrieved and isn't cited. Mochon, Norton and Ariely's 2008 paper on frequent small boosts to happiness wasn't looked up. Wood and Neal's 2007 theoretical paper on habits wasn't found in the database searched, and the 2016 review covers the same ground.