Fun facts from the 12 Journeys

Giant Brain Candy

96 surprising findings from the research beneath the journeys. Every card names its source; open “The research” on any card for the full reference.

AllNon-ConsciousnessAwarenessGriefAcceptanceGratitudeEmpowermentUncertaintyAbundanceVisionSurrenderNurtureLegacy

Journey 1Non-Consciousness

Giant Brain Candy: 86 Billion Neurons. Your brain holds about 86 billion neurons. Scientists counted them by dissolving brain tissue into a ‘soup’ of cell nuclei and tallying samples of it. Source: Counting the brain’s cells.
Strong evidenceThe research
  1. Azevedo, F. A. C., Carvalho, L. R. B., Grinberg, L. T., Farfel, J. M., Ferretti, R. E. L., Leite, R. E. P., Jacob Filho, W., Lent, R., & Herculano-Houzel, S. (2009). Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain. Journal of Comparative Neurology, 513(5), 532–541.
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Giant Brain Candy: The Other 85 Billion. Neurons have partners: about 85 billion other cells, mostly glia — astrocytes, oligodendrocytes and microglia. The old claim of ten glia for every neuron turned out to be a myth. Source: Neurons and glia, counted.
Strong evidenceThe research
  1. Azevedo, F. A. C., Carvalho, L. R. B., Grinberg, L. T., Farfel, J. M., Ferretti, R. E. L., Leite, R. E. P., Jacob Filho, W., Lent, R., & Herculano-Houzel, S. (2009). Equal numbers of neuronal and nonneuronal cells make the human brain an isometrically scaled-up primate brain. Journal of Comparative Neurology, 513(5), 532–541.
  2. von Bartheld, C. S., Bahney, J., & Herculano-Houzel, S. (2016). The search for true numbers of neurons and glial cells in the human brain: A review of 150 years of cell counting. Journal of Comparative Neurology, 524(18), 3865–3895.
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Giant Brain Candy: A 20-Watt Supercomputer. Your brain runs on about 20 watts, roughly a dim light bulb. It is only 2% of your body weight, yet it uses about 20% of your body’s energy. Source: The brain’s energy budget.
Strong evidenceThe research
  1. Balasubramanian, V. (2021). Brain power. Proceedings of the National Academy of Sciences, 118(32), e2107022118.
  2. Raichle, M. E., & Gusnard, D. A. (2002). Appraising the brain’s energy budget. Proceedings of the National Academy of Sciences, 99(16), 10237–10239.
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Giant Brain Candy: Wiring That Circles the Earth. Laid end to end, the brain’s insulated nerve fibres stretch roughly 150,000 to 180,000 km at their peak — enough to wrap around the Earth about four times. Source: Myelinated fibres, measured.
Growing evidenceThe research
  1. Marner, L., Nyengaard, J. R., Tang, Y., & Pakkenberg, B. (2003). Marked loss of myelinated nerve fibers in the human brain with age. Journal of Comparative Neurology, 462(2), 144–152.
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Giant Brain Candy: A Petabyte-Scale Memory?. One famous estimate puts the brain’s storage near 2.5 petabytes — about 3 million hours of TV. It’s a rough calculation, but it hints at how vast memory may be. Source: Estimating memory capacity.
A working modelThe research
  1. Reber, P. (2010). What is the memory capacity of the human brain? Scientific American Mind, 21(2), 70.
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Giant Brain Candy: Fire Together, Wire Together. Connections used together grow stronger. Hebb proposed it in 1949, and in 1973 researchers saw it happen: bursts of repeated signals strengthened links between neurons in rabbits for up to ten hours. Source: Hebbian learning and LTP.
Strong evidenceThe research
  1. Hebb, D. O. (1949). The organization of behavior: A neuropsychological theory. Wiley.
  2. Bliss, T. V. P., & Lømo, T. (1973). Long-lasting potentiation of synaptic transmission in the dentate area of the anaesthetized rabbit following stimulation of the perforant path. The Journal of Physiology, 232(2), 331–356.
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Giant Brain Candy: A Third to Half on Autopilot. In two diary studies, 35% and 43% of what people did were habits, done almost daily in the same place, and while doing them their thoughts were more often on something else. Source: Habits in everyday life.
Growing evidenceThe research
  1. Wood, W., Quinn, J. M., & Kashy, D. A. (2002). Habits in everyday life: Thought, emotion, and action. Journal of Personality and Social Psychology, 83(6), 1281–1297.
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Giant Brain Candy: The Taxi Drivers’ Brains. London taxi drivers, who memorise the city’s maze of streets, had a larger rear hippocampus than people who didn’t drive taxis, and the longer they had driven a taxi, the larger it was. Source: Navigation and the hippocampus.
Strong evidenceThe research
  1. Maguire, E. A., Gadian, D. G., Johnsrude, I. S., Good, C. D., Ashburner, J., Frackowiak, R. S. J., & Frith, C. D. (2000). Navigation-related structural change in the hippocampi of taxi drivers. Proceedings of the National Academy of Sciences, 97(8), 4398–4403.
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Giant Brain Candy: A Mind Away Half the Time. Pinged at random through the day, people’s minds were wandering about 47% of the time — and they felt less happy when they were. Source: Mind-wandering and happiness.
Growing evidenceThe research
  1. Killingsworth, M. A., & Gilbert, D. T. (2010). A wandering mind is an unhappy mind. Science, 330(6006), 932.
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The Non-Consciousness Deep Dive: the research, seminar by seminar →

Journey 2Awareness

Giant Brain Candy: A Word That Quiets the Alarm. When people chose a word for the feeling on an emotional face, like ‘angry’ or ‘scared’, their amygdala, the brain’s alarm, responded less, and a prefrontal region grew more active. Source: Putting feelings into words.
Strong evidenceThe research
  1. Lieberman, M. D., Eisenberger, N. I., Crockett, M. J., Tom, S. M., Pfeifer, J. H., & Way, B. M. (2007). Putting feelings into words: Affect labeling disrupts amygdala activity in response to affective stimuli. Psychological Science, 18(5), 421–428.
  2. Torre, J. B., & Lieberman, M. D. (2018). Putting feelings into words: Affect labeling as implicit emotion regulation. Emotion Review, 10(2), 116–124.
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Giant Brain Candy: Say It to the Spider. People afraid of spiders who put their fear into words beside a live tarantula showed a smaller bodily fear response a week later, facing a different spider in another setting, than those who reframed or distracted. Source: Naming fear during exposure.
Growing evidenceThe research
  1. Kircanski, K., Lieberman, M. D., & Craske, M. G. (2012). Feelings into words: Contributions of language to exposure therapy. Psychological Science, 23(10), 1086–1091.
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Giant Brain Candy: The Invisible Gorilla. Asked to count basketball passes in a short video, about half of viewers never noticed a person in a gorilla suit strolling right through the game. Source: Inattentional blindness.
Strong evidenceThe research
  1. Simons, D. J., & Chabris, C. F. (1999). Gorillas in our midst: Sustained inattentional blindness for dynamic events. Perception, 28(9), 1059–1074.
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Giant Brain Candy: Repeat It Till It Loses Its Sting. In one small study of eight people, saying a harsh word about yourself out loud, fast, for thirty seconds made it less believable and less upsetting than distraction or trying to control the thought. Source: Cognitive defusion.
Growing evidenceThe research
  1. Masuda, A., Hayes, S. C., Sackett, C. F., & Twohig, M. P. (2004). Cognitive defusion and self-relevant negative thoughts: Examining the impact of a ninety year old technique. Behaviour Research and Therapy, 42(4), 477–485.
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Giant Brain Candy: Solomon’s Paradox. People reason more wisely about a friend’s relationship trouble than about their own. Picture your own from a distance, and the gap disappears. Source: Self-distancing and wise reasoning.
Strong evidenceThe research
  1. Grossmann, I., & Kross, E. (2014). Exploring Solomon’s paradox: Self-distancing eliminates the self-other asymmetry in wise reasoning about close relationships in younger and older adults. Psychological Science, 25(8), 1571–1580.
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Giant Brain Candy: The Second Arrow. An early Buddhist teaching likens pain to being struck by a dart, and the untrained reaction, the sorrow and protest we add on top, to being struck by a second. Source: The parable of the second arrow.
Guiding wisdomThe research
  1. Bodhi, B. (Trans.). (2000). The connected discourses of the Buddha: A translation of the Saṃyutta Nikāya. Wisdom Publications.
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Giant Brain Candy: The Bias Blind Spot. People readily spot bias in others, yet rate themselves as less biased than the average person. Psychologists call it the bias blind spot. Source: Seeing bias in self and others.
Strong evidenceThe research
  1. Pronin, E., Lin, D. Y., & Ross, L. (2002). The bias blind spot: Perceptions of bias in self versus others. Personality and Social Psychology Bulletin, 28(3), 369–381.
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The Awareness Deep Dive: the research, seminar by seminar →

Journey 3Grief

Giant Brain Candy: The Stages Began With the Dying. The five stages first described patients facing their own deaths, not people grieving a loss. In 233 bereaved people, acceptance was what they reported most, from the first month on. Source: Testing the five stages.
Growing evidenceThe research
  1. Kübler-Ross, E. (1969). On death and dying. Macmillan.
  2. Maciejewski, P. K., Zhang, B., Block, S. D., & Prigerson, H. G. (2007). An empirical examination of the stage theory of grief. JAMA, 297(7), 716–723.
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Giant Brain Candy: Bending Without Breaking. Following people from years before a spouse died to 18 months after, researchers found resilience was the most common pattern: real sorrow, with daily life holding its shape. Source: Resilience after loss.
Strong evidenceThe research
  1. Bonanno, G. A., Wortman, C. B., Lehman, D. R., Tweed, R. G., Haring, M., Sonnega, J., Carr, D., & Nesse, R. M. (2002). Resilience to loss and chronic grief: A prospective study from preloss to 18-months postloss. Journal of Personality and Social Psychology, 83(5), 1150–1164.
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Giant Brain Candy: A Word Born Heavy. The English word grief comes, through Old French, from the Latin gravare, ‘to make heavy’, which comes from gravis, ‘weighty’. Source: The roots of the word grief.
Strong evidenceThe research
  1. Harper, D. (n.d.). Grief. In Online Etymology Dictionary. etymonline.com.
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Giant Brain Candy: Grief as a Kind of Learning. Grief researcher Mary-Frances O’Connor describes grieving as a form of learning: for years your brain expected someone to be there, and updating that takes time and lived experience. Source: Grieving as learning.
A working modelThe research
  1. O'Connor, M.-F., & Seeley, S. H. (2022). Grieving as a form of learning: Insights from neuroscience applied to grief and loss. Current Opinion in Psychology, 43, 317–322.
  2. O'Connor, M.-F. (2022). The grieving brain: The surprising science of how we learn from love and loss. HarperOne.
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Giant Brain Candy: Yearning Looks Like Wanting. In a small brain-scan study, reminders of a loved one who had died activated a reward region, the nucleus accumbens, only in people with complicated grief, in step with how strongly they yearned. Source: Yearning and the reward system.
Growing evidenceThe research
  1. O'Connor, M.-F., Wellisch, D. K., Stanton, A. L., Eisenberger, N. I., Irwin, M. R., & Lieberman, M. D. (2008). Craving love? Enduring grief activates brain's reward center. NeuroImage, 42(2), 969–972.
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Giant Brain Candy: A Broken Heart Can Mend. Sudden emotional shock can weaken the heart muscle, a condition nicknamed ‘broken heart syndrome’. In one well-known series of 19 patients, every heart recovered within weeks. Source: Takotsubo cardiomyopathy.
Strong evidenceThe research
  1. Wittstein, I. S., Thiemann, D. R., Lima, J. A. C., Baughman, K. L., Schulman, S. P., Gerstenblith, G., Wu, K. C., Rade, J. J., Bivalacqua, T. J., & Champion, H. C. (2005). Neurohumoral features of myocardial stunning due to sudden emotional stress. New England Journal of Medicine, 352(6), 539–548.
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Giant Brain Candy: Feeling Them Near. In a classic survey of 293 widowed people, almost half had sensed their late spouse after the death: a presence, a voice or a glimpse. The researcher found it normal and often helpful. Source: Sensing a loved one’s presence.
Growing evidenceThe research
  1. Rees, W. D. (1971). The hallucinations of widowhood. British Medical Journal, 4(5778), 37–41.
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Giant Brain Candy: Being There Beats Advice. Asked what helped after a sudden loss, bereaved people named presence, concern and a chance to talk. Advice, pushes to recover and ‘I know how you feel’ often felt unhelpful. Source: What helps the bereaved.
Growing evidenceThe research
  1. Lehman, D. R., Ellard, J. H., & Wortman, C. B. (1986). Social support for the bereaved: Recipients' and providers' perspectives on what is helpful. Journal of Consulting and Clinical Psychology, 54(4), 438–446.
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The Grief Deep Dive: the research, seminar by seminar →

Journey 4Acceptance

Giant Brain Candy: Don’t Think of a White Bear. Told not to think of a white bear for five minutes, people couldn’t keep it out. When later asked to think of it, they thought of it more than people asked to think of it from the start. Source: The white bear experiment.
Strong evidenceThe research
  1. Wegner, D. M., Schneider, D. J., Carter, S. R., III, & White, T. L. (1987). Paradoxical effects of thought suppression. Journal of Personality and Social Psychology, 53(1), 5–13.
  2. Abramowitz, J. S., Tolin, D. F., & Street, G. P. (2001). Paradoxical effects of thought suppression: A meta-analysis of controlled studies. Clinical Psychology Review, 21(5), 683–703.
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Giant Brain Candy: What a Poker Face Costs. Asked to hide their feelings while watching a disgusting film, people’s faces went still, but they felt just as disgusted, and signs of stress arousal in their bodies rose. Source: Emotional suppression.
Strong evidenceThe research
  1. Gross, J. J., & Levenson, R. W. (1993). Emotional suppression: Physiology, self-report, and expressive behavior. Journal of Personality and Social Psychology, 64(6), 970–986.
  2. Gross, J. J. (1998). Antecedent- and response-focused emotion regulation: Divergent consequences for experience, expression, and physiology. Journal of Personality and Social Psychology, 74(1), 224–237.
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Giant Brain Candy: Accepting Pain, Living More. Among 230 people with chronic pain, accepting it went with less disability and depression, more time up and active, and better work status. It predicted these better than the coping strategies they used. Source: Acceptance of chronic pain.
Strong evidenceThe research
  1. McCracken, L. M., & Eccleston, C. (2003). Coping or acceptance: What to do about chronic pain? Pain, 105(1–2), 197–204.
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Giant Brain Candy: Let the Feeling Be a Feeling. People who habitually accept their negative thoughts and feelings, rather than judging them, had better mental health six months later, partly because daily stress upset them less. Source: Accepting negative emotions.
Strong evidenceThe research
  1. Ford, B. Q., Lam, P., John, O. P., & Mauss, I. B. (2018). The psychological health benefits of accepting negative emotions and thoughts: Laboratory, diary, and longitudinal evidence. Journal of Personality and Social Psychology, 115(6), 1075–1092.
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Giant Brain Candy: Two Weeks to Less Lonely. A two-week smartphone course in noticing and accepting experience cut daily loneliness by 22% and added about two social interactions a day. The same course without the acceptance lessons didn’t. Source: Mindfulness with acceptance.
Growing evidenceThe research
  1. Lindsay, E. K., Young, S., Brown, K. W., Smyth, J. M., & Creswell, J. D. (2019). Mindfulness training reduces loneliness and increases social contact in a randomized controlled trial. Proceedings of the National Academy of Sciences, 116(9), 3488–3493.
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Giant Brain Candy: The Power of a Long Exhale. In one month-long study, five minutes a day of breathing with long, slow exhales lifted mood more than the same five minutes spent in mindfulness meditation. Source: Exhale-focused breathing.
Growing evidenceThe research
  1. Balban, M. Y., Neri, E., Kogon, M. M., Weed, L., Nouriani, B., Jo, B., Holl, G., Zeitzer, J. M., Spiegel, D., & Huberman, A. D. (2023). Brief structured respiration practices enhance mood and reduce physiological arousal. Cell Reports Medicine, 4(1), 100895.
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Giant Brain Candy: Rosy Daydreams Sap Energy. In experiments, people who fantasised only about an ideal future, with no obstacles in sight, showed less energy, measured partly as lower blood pressure. Source: Positive fantasies and energy.
Growing evidenceThe research
  1. Kappes, H. B., & Oettingen, G. (2011). Positive fantasies about idealized futures sap energy. Journal of Experimental Social Psychology, 47(4), 719–729.
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The Acceptance Deep Dive: the research, seminar by seminar →

Journey 5Gratitude

Giant Brain Candy: It’s the Meaning, Not the Gift. People who read the very same story of being helped felt more grateful when they saw the help as more valuable, more costly to the helper and more freely given. Changing those features changed how grateful people felt. Source: Appraising a kindness.
Strong evidenceThe research
  1. Wood, A. M., Maltby, J., Stewart, N., Linley, P. A., & Joseph, S. (2008). A social-cognitive model of trait and state levels of gratitude. Emotion, 8(2), 281–290.
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Giant Brain Candy: The Thank-You Letter Visit. In an online trial of happiness exercises, writing a thank-you letter and delivering it in person gave the biggest immediate lift of all. The boost lasted about a month. Source: The gratitude visit.
Growing evidenceThe research
  1. Seligman, M. E. P., Steen, T. A., Park, N., & Peterson, C. (2005). Positive psychology progress: Empirical validation of interventions. American Psychologist, 60(5), 410–421.
  2. Mongrain, M., & Anselmo-Matthews, T. (2012). Do positive psychology exercises work? A replication of Seligman et al. (2005). Journal of Clinical Psychology, 68(4), 382–389.
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Giant Brain Candy: Your Thanks Mean More Than You Think. People writing thank-you letters underestimated how surprised and pleased recipients would be, and overestimated how awkward recipients would feel. The more awkwardness they expected, the less willing they were to write. Source: Undervaluing gratitude.
Strong evidenceThe research
  1. Kumar, A., & Epley, N. (2018). Undervaluing gratitude: Expressers misunderstand the consequences of showing appreciation. Psychological Science, 29(9), 1423–1435.
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Giant Brain Candy: Thanks That Spread to Bystanders. Across eight experiments with 1,817 people, those who simply watched someone thank another person became more helpful toward the grateful person and more drawn to both of them. Source: The witnessing effect.
Growing evidenceThe research
  1. Algoe, S. B., Dwyer, P. C., Younge, A., & Oveis, C. (2020). A new perspective on the social functions of emotions: Gratitude and the witnessing effect. Journal of Personality and Social Psychology, 119(1), 40–74.
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Giant Brain Candy: Imagine It Never Happened. People who wrote about how a good thing in their life might never have happened felt better than people who wrote about how it came to be, and those asked to predict it didn’t see it coming. Source: Mental subtraction.
Growing evidenceThe research
  1. Koo, M., Algoe, S. B., Wilson, T. D., & Gilbert, D. T. (2008). It’s a wonderful life: Mentally subtracting positive events improves people’s affective states, contrary to their affective forecasts. Journal of Personality and Social Psychology, 95(5), 1217–1224.
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Giant Brain Candy: Send It, Don’t Just List It. In an experiment spanning 34 countries, writing and sending a gratitude message gave the biggest immediate boost of six gratitude practices. Simply listing blessings gave the smallest. Source: A 34-country gratitude study.
Growing evidenceThe research
  1. Coles, N. A., Dang, A. V., Oishi, S., et al. (2026). A multinational megastudy of the effects of gratitude practices on subjective well-being. Proceedings of the National Academy of Sciences, 123(20), e2537789123.
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Giant Brain Candy: A Smile Can Start the Feeling. In a test across 19 countries, deliberately posing a smile could amplify, and even spark, feelings of happiness. The effect is small, but it’s real. Source: The facial feedback effect.
Strong evidenceThe research
  1. Coles, N. A., March, D. S., Marmolejo-Ramos, F., et al. (2022). A multi-lab test of the facial feedback hypothesis by the Many Smiles Collaboration. Nature Human Behaviour, 6(12), 1731–1742.
  2. Coles, N. A., Larsen, J. T., & Lench, H. C. (2019). A meta-analysis of the facial feedback literature: Effects of facial feedback on emotional experience are small and variable. Psychological Bulletin, 145(6), 610–651.
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Giant Brain Candy: Gratitude Helps You Wait. In one experiment, people made to feel grateful were more patient with real money at stake, more willing to wait for a larger reward, and the effect wasn’t just from feeling happy. Source: Gratitude and patience.
Growing evidenceThe research
  1. DeSteno, D., Li, Y., Dickens, L., & Lerner, J. S. (2014). Gratitude: A tool for reducing economic impatience. Psychological Science, 25(6), 1262–1267.
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The Gratitude Deep Dive: the research, seminar by seminar →

Journey 6Empowerment

Giant Brain Candy: Don’t Calm Down. Get Excited.. Asked how to handle nerves, about nine in ten people pick ‘try to calm down’. Yet nervous singers who said ‘I am excited’ sang with about 81% accuracy, against 53% for ‘I am anxious’. Source: Reappraising nerves as excitement.
Growing evidenceThe research
  1. Brooks, A. W. (2014). Get excited: Reappraising pre-performance anxiety as excitement. Journal of Experimental Psychology: General, 143(3), 1144–1158.
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Giant Brain Candy: They Had It Backwards. Fifty years after discovering ‘learned helplessness’ in animals, its discoverers concluded they had it backwards: passivity under prolonged stress is the default, and what gets learned is control. Source: Learned helplessness at fifty.
Growing evidenceThe research
  1. Maier, S. F., & Seligman, M. E. P. (2016). Learned helplessness at fifty: Insights from neuroscience. Psychological Review, 123(4), 349–367.
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Giant Brain Candy: The Power of an Unpressed Button. People stuck with loud, unpredictable noise coped better afterwards, trying longer on frustrating puzzles, if they had a button that could stop it, even when they never used it. Source: Perceived control over stress.
Strong evidenceThe research
  1. Glass, D. C., & Singer, J. E. (1972). Urban stress: Experiments on noise and social stressors. Academic Press.
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Giant Brain Candy: Confidence Follows the Climb. Pooling studies that followed the same people across repeated tasks, researchers found self-belief was more a product of past performance than a driver of future performance. Source: Self-efficacy and performance.
Strong evidenceThe research
  1. Sitzmann, T., & Yeo, G. (2013). A meta-analytic investigation of the within-person self-efficacy domain: Is self-efficacy a product of past performance or a driver of future performance? Personnel Psychology, 66(3), 531–568.
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Giant Brain Candy: The Power of Small Wins. In nearly 12,000 daily diary entries from 238 professionals, motivation and mood rose on the days people made progress in meaningful work, very often through small wins. Source: The progress principle.
Growing evidenceThe research
  1. Amabile, T. M., & Kramer, S. J. (2011). The progress principle: Using small wins to ignite joy, engagement, and creativity at work. Harvard Business Review Press.
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Giant Brain Candy: What Power Poses Really Do. Two minutes of ‘power posing’ was said to change your hormones. A replication nearly five times larger found no hormone change, though people did feel a little more powerful. Source: Power posing, retested.
Growing evidenceThe research
  1. Carney, D. R., Cuddy, A. J. C., & Yap, A. J. (2010). Power posing: Brief nonverbal displays affect neuroendocrine levels and risk tolerance. Psychological Science, 21(10), 1363–1368.
  2. Ranehill, E., Dreber, A., Johannesson, M., Leiberg, S., Sul, S., & Weber, R. A. (2015). Assessing the robustness of power posing: No effect on hormones and risk tolerance in a large sample of men and women. Psychological Science, 26(5), 653–656.
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Giant Brain Candy: Courage Comes Before Calm. Psychologist Stanley Rachman studied people whose work demands courage, such as parachute trainees. With successful practice, acting despite fear tended to turn into fearlessness. Source: Courage becoming fearlessness.
Growing evidenceThe research
  1. Rachman, S. J. (1990). Fear and courage (2nd ed.). W. H. Freeman.
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Giant Brain Candy: Dopamine Loves a Surprise. In monkeys, dopamine neurons fire when a reward beats expectations, stay quiet when it is fully predicted, and dip when an expected reward fails to arrive. Source: Reward prediction error.
Strong evidenceThe research
  1. Schultz, W., Dayan, P., & Montague, P. R. (1997). A neural substrate of prediction and reward. Science, 275(5306), 1593–1599.
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The Empowerment Deep Dive: the research, seminar by seminar →

Journey 7Uncertainty

Giant Brain Candy: A Maybe Can Hurt More. People learning when painful shocks might come felt and showed the most stress when a shock was a 50/50 toss-up, not when it was certain to come. Source: Uncertainty and stress.
Growing evidenceThe research
  1. de Berker, A. O., Rutledge, R. B., Mathys, C., Marshall, L., Cross, G. F., Dolan, R. J., & Bestmann, S. (2016). Computations of uncertainty mediate acute stress responses in humans. Nature Communications, 7, 10996.
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Giant Brain Candy: The Worries That Never Came. People treated for chronic worry logged their worries for ten days and checked back 20 days later: 91.4% of the worries had not come true. Source: How often worries come true.
Growing evidenceThe research
  1. LaFreniere, L. S., & Newman, M. G. (2020). Exposing worry’s deceit: Percentage of untrue worries in generalized anxiety disorder treatment. Behavior Therapy, 51(3), 413–423.
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Giant Brain Candy: Check Again, Trust Less. People who checked a virtual gas stove again and again grew less sure they had checked it, as their memories grew less vivid, though their memory stayed just as accurate. Source: Repeated checking and memory.
Strong evidenceThe research
  1. van den Hout, M., & Kindt, M. (2003). Repeated checking causes memory distrust. Behaviour Research and Therapy, 41(3), 301–316.
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Giant Brain Candy: Curiosity Makes Memories Stick. Curiosity engages the brain’s reward circuits and boosts memory: when people were curious about a question, they remembered its answer better, and even unrelated faces shown while they waited. Source: Curiosity, reward and memory.
Strong evidenceThe research
  1. Kang, M. J., Hsu, M., Krajbich, I. M., Loewenstein, G., McClure, S. M., Wang, J. T., & Camerer, C. F. (2009). The wick in the candle of learning: Epistemic curiosity activates reward circuitry and enhances memory. Psychological Science, 20(8), 963–973.
  2. Gruber, M. J., Gelman, B. D., & Ranganath, C. (2014). States of curiosity modulate hippocampus-dependent learning via the dopaminergic circuit. Neuron, 84(2), 486–496.
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Giant Brain Candy: The Joy of Not Knowing Why. People handed a dollar coin on a card that made it hard to work out why stayed in a better mood than those given an easy explanation. People asked to predict this guessed the opposite. Source: The pleasures of uncertainty.
Growing evidenceThe research
  1. Wilson, T. D., Centerbar, D. B., Kermer, D. A., & Gilbert, D. T. (2005). The pleasures of uncertainty: Prolonging positive moods in ways people do not anticipate. Journal of Personality and Social Psychology, 88(1), 5–21.
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Giant Brain Candy: When a Coin Said ‘Change’. Thousands of people stuck on a big decision let a coin toss nudge them. Those it told to make a change were, on average, happier six months later, by their own ratings. Source: Coin tosses and big decisions.
Growing evidenceThe research
  1. Levitt, S. D. (2021). Heads or tails: The impact of a coin toss on major life decisions and subsequent happiness. The Review of Economic Studies, 88(1), 378–405.
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Giant Brain Candy: A Hand to Hold. Under threat of a mild shock, women’s threat-related brain activity eased when they held a hand: a little for a stranger’s, more for their partner’s, and more still in happier relationships. Source: Holding hands under threat.
Growing evidenceThe research
  1. Coan, J. A., Schaefer, H. S., & Davidson, R. J. (2006). Lending a hand: Social regulation of the neural response to threat. Psychological Science, 17(12), 1032–1039.
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Giant Brain Candy: Built Like a Smoke Alarm. When a false alarm is cheap and a missed fire is deadly, a well-designed alarm gives many false alarms. Psychiatrist Randolph Nesse argues our fear and anxiety are built the same way. Source: The smoke-detector principle.
A working modelThe research
  1. Nesse, R. M. (2019). Good reasons for bad feelings: Insights from the frontier of evolutionary psychiatry. Dutton.
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Giant Brain Candy: Guess Wrong, Learn Better. Trying to answer a question before learning it, and getting it wrong, helped people learn the answer better than simply studying it for the same amount of time. Source: Learning from wrong guesses.
Strong evidenceThe research
  1. Kornell, N., Hays, M. J., & Bjork, R. A. (2009). Unsuccessful retrieval attempts enhance subsequent learning. Journal of Experimental Psychology: Learning, Memory, and Cognition, 35(4), 989–998.
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The Uncertainty Deep Dive: the research, seminar by seminar →

Journey 8Abundance

Giant Brain Candy: Sharper After the Harvest. In one much-debated study, sugar-cane farmers in India scored lower on reasoning tests before harvest, when money was tight, than after it. The researchers argued the situation, not the person, caused the drop. Source: Scarcity and the mind’s bandwidth.
Growing evidenceThe research
  1. Mani, A., Mullainathan, S., Shafir, E., & Zhao, J. (2013a). Poverty impedes cognitive function. Science, 341(6149), 976–980.
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Giant Brain Candy: The Grades That Couldn’t Run Out. Even where top grades were unlimited, people who saw that many had already been given predicted a lower grade for the next presenter, as if good grades were running out. Source: Zero-sum bias.
Growing evidenceThe research
  1. Meegan, D. V. (2010). Zero-sum bias: Perceived competition despite unlimited resources. Frontiers in Psychology, 1, 191.
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Giant Brain Candy: Fighting Over the Same Thing. Across 32 negotiation experiments, when both sides wanted the same outcome on an issue, people failed to notice about half the time, and about one deal in five ended lose–lose. Source: Lose–lose agreements.
Strong evidenceThe research
  1. Thompson, L., & Hrebec, D. (1996). Lose–lose agreements in interdependent decision making. Psychological Bulletin, 120(3), 396–409.
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Giant Brain Candy: Give Time, Get Time. In four experiments, people who spent a little time helping someone else felt they had more time afterwards, even more than people handed a windfall of free time. Source: Giving time and time affluence.
Growing evidenceThe research
  1. Mogilner, C., Chance, Z., & Norton, M. I. (2012). Giving time gives you time. Psychological Science, 23(10), 1233–1238.
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Giant Brain Candy: More Yeses Than You Think. People asking for help underestimated by as much as half how many others would say yes, and they underestimated how good the helpers would feel about helping. Source: Underestimating helpfulness.
Strong evidenceThe research
  1. Flynn, F. J., & Lake, V. K. B. (2008). If you need help, just ask: Underestimating compliance with direct requests for help. Journal of Personality and Social Psychology, 95(1), 128–143.
  2. Zhao, X., & Epley, N. (2022). Surprisingly happy to have helped: Underestimating prosociality creates a misplaced barrier to asking for help. Psychological Science, 33(10), 1708–1731.
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Giant Brain Candy: Wanting Isn’t Liking. Rats with almost all their brain dopamine depleted stopped seeking food, yet still showed normal signs of liking sugar on the tongue. Dopamine drives wanting more than enjoying. Source: Wanting versus liking.
Strong evidenceThe research
  1. Berridge, K. C., & Robinson, T. E. (1998). What is the role of dopamine in reward: Hedonic impact, reward learning, or incentive salience? Brain Research Reviews, 28(3), 309–369.
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Giant Brain Candy: What a Big Win Really Does. A large Swedish study found that big lottery wins raised winners’ life satisfaction for more than a decade, with much smaller effects on happiness and mental health. Source: Lottery wealth and well-being.
Growing evidenceThe research
  1. Lindqvist, E., Östling, R., & Cesarini, D. (2020). Long-run effects of lottery wealth on psychological well-being. The Review of Economic Studies, 87(6), 2703–2726.
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The Abundance Deep Dive: the research, seminar by seminar →

Journey 9Vision

Giant Brain Candy: Remembering the Future. Imagining a moment in your own future uses much of the same brain network as remembering your past. Scientists call it the prospective brain. Source: The prospective brain.
Strong evidenceThe research
  1. Schacter, D. L., Addis, D. R., & Buckner, R. L. (2007). Remembering the past to imagine the future: The prospective brain. Nature Reviews Neuroscience, 8(9), 657–661.
  2. Benoit, R. G., & Schacter, D. L. (2015). Specifying the core network supporting episodic simulation and episodic memory by activation likelihood estimation. Neuropsychologia, 75, 450–457.
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Giant Brain Candy: The Daydream Penalty. In one small study of a year-long weight-loss programme, women with the most glowing daydreams of success lost about 24 pounds less than women whose imaginings included the struggle. Source: Positive fantasies and effort.
Growing evidenceThe research
  1. Oettingen, G., & Wadden, T. A. (1991). Expectation, fantasy, and weight loss: Is the impact of positive thinking always positive? Cognitive Therapy and Research, 15(2), 167–175.
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Giant Brain Candy: Picture the Path, Not the Prize. In the week before an exam, people who spent five minutes a day picturing how they would study scored nearly eight points higher than controls. Picturing the top grade added only about two. Source: Process versus outcome simulation.
Growing evidenceThe research
  1. Taylor, S. E., Pham, L. B., Rivkin, I. D., & Armor, D. A. (1998). Harnessing the imagination: Mental simulation, self-regulation, and coping. American Psychologist, 53(4), 429–439.
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Giant Brain Candy: One Session, Twice as Active. Women who learned, in one session, to name a wish, its main obstacle and an if-then plan were about twice as physically active over the next four months as women given health information alone. Source: Mental contrasting with if-then plans.
Growing evidenceThe research
  1. Stadler, G., Oettingen, G., & Gollwitzer, P. M. (2009). Physical activity in women: Effects of a self-regulation intervention. American Journal of Preventive Medicine, 36(1), 29–34.
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Giant Brain Candy: ‘Should’ Means ‘Owe’. ‘Should’ began as the past tense of Old English sceal: ‘I owe, I ought to, I must’. It shares a Germanic root with German Schuld, which means guilt or debt. Source: Where ‘should’ comes from.
Strong evidenceThe research
  1. Harper, D. (n.d.). Shall (v.); Should (v.). In Online Etymology Dictionary. Retrieved September 26, 2026, from https://www.etymonline.com/word/should
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Giant Brain Candy: Telling Can Feel Like Doing. In three experiments, people whose plans for who they wanted to become were noticed by others acted on them less. A fourth found being noticed gave a premature sense of already being that person. Source: When intentions go public.
Growing evidenceThe research
  1. Gollwitzer, P. M., Sheeran, P., Michalski, V., & Seifert, A. E. (2009). When intentions go public: Does social reality widen the intention–behavior gap? Psychological Science, 20(5), 612–618.
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Giant Brain Candy: Minds Without Pictures. Some people have no voluntary visual imagery at all: when they try to picture something, nothing appears. In 2015 researchers named this aphantasia, describing people with little or no imagery all their lives. Source: Lives without imagery.
Strong evidenceThe research
  1. Zeman, A., Dewar, M., & Della Sala, S. (2015). Lives without imagery – Congenital aphantasia. Cortex, 73, 378–380.
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The Vision Deep Dive: the research, seminar by seminar →

Journey 10Surrender

Giant Brain Candy: Born to Choose. People, and other animals, often prefer having a choice even when choosing wins them nothing extra. The need to feel in control runs that deep. Source: The need for control.
Strong evidenceThe research
  1. Leotti, L. A., Iyengar, S. S., & Ochsner, K. N. (2010). Born to choose: The origins and value of the need for control. Trends in Cognitive Sciences, 14(10), 457–463.
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Giant Brain Candy: Out of Control, and Judged. Across 208 lab studies, the stress tests that raised cortisol most, and kept it high longest, combined two things: no control over the task, and other people judging. Source: Cortisol, control and judgement.
Strong evidenceThe research
  1. Dickerson, S. S., & Kemeny, M. E. (2004). Acute stressors and cortisol responses: A theoretical integration and synthesis of laboratory research. Psychological Bulletin, 130(3), 355–391.
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Giant Brain Candy: Let Go, Then Begin Again. People who could let go of goals that had become unreachable, and take up new ones, reported higher well-being. Both halves mattered: releasing the old goal and reaching for a new one. Source: Letting go of unreachable goals.
Growing evidenceThe research
  1. Wrosch, C., Scheier, M. F., Miller, G. E., Schulz, R., & Carver, C. S. (2003). Adaptive self-regulation of unattainable goals: Goal disengagement, goal reengagement, and subjective well-being. Personality and Social Psychology Bulletin, 29(12), 1494–1508.
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Giant Brain Candy: Calm Can Take Effort at First. After three short daily sessions of mindfulness training, people felt less stressed in a tough speech test, yet their cortisol rose more than a comparison group’s. Letting go may take effort at first. Source: Mindfulness and stress hormones.
Growing evidenceThe research
  1. Creswell, J. D., Pacilio, L. E., Lindsay, E. K., & Brown, K. W. (2014). Brief mindfulness meditation training alters psychological and neuroendocrine responses to social evaluative stress. Psychoneuroendocrinology, 44, 1–12.
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Giant Brain Candy: The Jazz Pianist’s Quiet Mind. When six professional jazz pianists improvised inside a brain scanner, wide areas of the prefrontal cortex linked to self-monitoring went quiet. Source: The brain improvising jazz.
Growing evidenceThe research
  1. Limb, C. J., & Braun, A. R. (2008). Neural substrates of spontaneous musical performance: An fMRI study of jazz improvisation. PLoS ONE, 3(2), e1679.
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Giant Brain Candy: Practise Being Watched. People new to golf who practised putting while being filmed for experts to review held up under pressure later. Those who had practised with distractions instead still choked. Source: Choking under pressure.
Growing evidenceThe research
  1. Beilock, S. L., & Carr, T. H. (2001). On the fragility of skilled performance: What governs choking under pressure? Journal of Experimental Psychology: General, 130(4), 701–725.
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Giant Brain Candy: Up to Us, or Not. The Handbook of Epictetus, written down about 1,900 years ago, opens by sorting life in two: what is up to us, like our judgements and desires, and what is not. Source: The Stoics’ ‘up to us’.
Guiding wisdomThe research
  1. Epictetus. (1983). Handbook of Epictetus (N. P. White, Trans.). Hackett. (Original work compiled ca. 125 CE)
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Giant Brain Candy: Push, and People Push Back. When people feel their freedom is threatened, they push back to win it back, sometimes by doing the very thing they were pressed not to do. Psychologists call it reactance. Source: Psychological reactance.
A working modelThe research
  1. Brehm, J. W. (1966). A theory of psychological reactance. Academic Press.
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The Surrender Deep Dive: the research, seminar by seminar →

Journey 11Nurture

Giant Brain Candy: The Jugglers’ Growing Brains. People who learned to juggle for three months grew measurably more grey matter in brain areas that track motion. When they stopped practising, the growth faded. Source: Juggling and grey matter.
Strong evidenceThe research
  1. Draganski, B., Gaser, C., Busch, V., Schuierer, G., Bogdahn, U., & May, A. (2004). Neuroplasticity: Changes in grey matter induced by training. Nature, 427(6972), 311–312.
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Giant Brain Candy: Kindness Beat the Ego Boost. After failing a hard test, people encouraged to be kind to themselves studied longer for a retake than people given a boost to their self-esteem. Source: Self-compassion after failure.
Growing evidenceThe research
  1. Breines, J. G., & Chen, S. (2012). Self-compassion increases self-improvement motivation. Personality and Social Psychology Bulletin, 38(9), 1133–1143.
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Giant Brain Candy: The Doughnut Experiment. In one small study, people who usually restrict what they eat tended to eat fewer sweets after a doughnut if they had been told kindly that everyone eats unhealthily sometimes. Source: Self-compassion and eating.
Growing evidenceThe research
  1. Adams, C. E., & Leary, M. R. (2007). Promoting self-compassionate attitudes toward eating among restrictive and guilty eaters. Journal of Social and Clinical Psychology, 26(10), 1120–1144.
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Giant Brain Candy: The Hidden Cost of Six Hours. After two weeks of sleeping six hours a night or less, people performed as badly as after up to two nights with no sleep at all, yet felt only a little sleepy. Source: The cumulative cost of short sleep.
Strong evidenceThe research
  1. Van Dongen, H. P. A., Maislin, G., Mullington, J. M., & Dinges, D. F. (2003). The cumulative cost of additional wakefulness: Dose-response effects on neurobehavioral functions and sleep physiology from chronic sleep restriction and total sleep deprivation. Sleep, 26(2), 117–126.
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Giant Brain Candy: Ten Quiet Minutes. In one small study, people rested quietly for ten minutes after hearing one short story and played a game after another. A week later, they remembered more of the story followed by rest. Source: Wakeful rest and memory.
Growing evidenceThe research
  1. Dewar, M., Alber, J., Butler, C., Cowan, N., & Della Sala, S. (2012). Brief wakeful resting boosts new memories over the long term. Psychological Science, 23(9), 955–960.
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Giant Brain Candy: Gains Show Up in the Pauses. When people practised a new finger sequence in ten-second bursts, their early gains showed up across the ten-second breaks, not during practice. Why is still debated. Source: Learning during short rests.
Growing evidenceThe research
  1. Bönstrup, M., Iturrate, I., Thompson, R., Cruciani, G., Censor, N., & Cohen, L. G. (2019). A rapid form of offline consolidation in skill learning. Current Biology, 29(8), 1346–1351.e4.
  2. Gupta, M. W., & Rickard, T. C. (2022). Dissipation of reactive inhibition is sufficient to explain post-rest improvements in motor sequence learning. npj Science of Learning, 7, Article 25.
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Giant Brain Candy: More Hugs, Milder Colds. Researchers tracked 404 people’s hugs for two weeks, then exposed them to a cold virus. Among those who got infected, people hugged more often showed milder signs of illness. Source: Hugs, support and the cold virus.
Growing evidenceThe research
  1. Cohen, S., Janicki-Deverts, D., Turner, R. B., & Doyle, W. J. (2015). Does hugging provide stress-buffering social support? A study of susceptibility to upper respiratory infection and illness. Psychological Science, 26(2), 135–147.
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Giant Brain Candy: Is Happiness Catching?. In a 20-year study of one town, a friend nearby becoming happy raised a person’s chance of happiness by about 25%. But similar methods also ‘spread’ acne and height, so it’s debated. Source: Happiness in social networks.
Growing evidenceThe research
  1. Fowler, J. H., & Christakis, N. A. (2008). Dynamic spread of happiness in a large social network: Longitudinal analysis over 20 years in the Framingham Heart Study. BMJ, 337, a2338.
  2. Cohen-Cole, E., & Fletcher, J. M. (2008). Detecting implausible social network effects in acne, height, and headaches: Longitudinal analysis. BMJ, 337, a2533.
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Giant Brain Candy: Stronger Ties, Longer Lives. Across 148 studies of over 300,000 people, stronger social relationships went with about 50% greater odds of survival, comparable to well-known risk factors for mortality. Source: Social relationships and survival.
Strong evidenceThe research
  1. Holt-Lunstad, J., Smith, T. B., & Layton, J. B. (2010). Social relationships and mortality risk: A meta-analytic review. PLoS Medicine, 7(7), e1000316.
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The Nurture Deep Dive: the research, seminar by seminar →

Journey 12Legacy

Giant Brain Candy: Giving Lights Up Like Getting. In brain scans, giving money to charity engaged the same reward circuitry as receiving money. Even a forced, tax-like payment to charity did, and choosing to give did more. Source: Giving and the brain’s reward system.
Growing evidenceThe research
  1. Moll, J., Krueger, F., Zahn, R., Pardini, M., de Oliveira-Souza, R., & Grafman, J. (2006). Human fronto–mesolimbic networks guide decisions about charitable donation. Proceedings of the National Academy of Sciences, 103(42), 15623–15628.
  2. Harbaugh, W. T., Mayr, U., & Burghart, D. R. (2007). Neural responses to taxation and voluntary giving reveal motives for charitable donations. Science, 316(5831), 1622–1625.
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Giant Brain Candy: Generosity Travels Three Steps. In group games among strangers, cooperation spread from person to person, up to three steps away. Each extra contribution in the first round was roughly tripled by the end. Source: Cooperation cascades.
Growing evidenceThe research
  1. Fowler, J. H., & Christakis, N. A. (2010). Cooperative behavior cascades in human social networks. Proceedings of the National Academy of Sciences, 107(12), 5334–5338.
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Giant Brain Candy: Meet One Face, Double the Effort. Fundraising callers who spent a few minutes with a scholarship recipient their calls helped fund went on to more than double their phone time and the money they raised. Source: Meeting the people you help.
Growing evidenceThe research
  1. Grant, A. M., Campbell, E. M., Chen, G., Cottone, K., Lapedis, D., & Lee, K. (2007). Impact and the art of motivation maintenance: The effects of contact with beneficiaries on persistence behavior. Organizational Behavior and Human Decision Processes, 103(1), 53–67.
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Giant Brain Candy: Why You Give Matters. In one large study, people who volunteered for others’ sake were less likely to die over the next four years. Those who volunteered mainly for themselves had about the same risk as non-volunteers. Source: Motives for volunteering.
Growing evidenceThe research
  1. Konrath, S., Fuhrel-Forbis, A., Lou, A., & Brown, S. (2012). Motives for volunteering are associated with mortality risk in older adults. Health Psychology, 31(1), 87–96.
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Giant Brain Candy: Purpose and a Longer Life. Among about 6,000 people followed for 14 years, those with a stronger sense of purpose were less likely to die in that time. Other studies find the same modest link, though it isn’t proof of cause. Source: Purpose and longevity.
Strong evidenceThe research
  1. Hill, P. L., & Turiano, N. A. (2014). Purpose in life as a predictor of mortality across adulthood. Psychological Science, 25(7), 1482–1486.
  2. Cohen, R., Bavishi, C., & Rozanski, A. (2016). Purpose in life and its relationship to all-cause mortality and cardiovascular events: A meta-analysis. Psychosomatic Medicine, 78(2), 122–133.
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Giant Brain Candy: Hard Times, Helping Hands. In a five-year study, stressful life events went with a higher risk of dying, but only among people who were not helping others. Source: Giving, stress and mortality.
Growing evidenceThe research
  1. Poulin, M. J., Brown, S. L., Dillard, A. J., & Smith, D. M. (2013). Giving to others and the association between stress and mortality. American Journal of Public Health, 103(9), 1649–1655.
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Giant Brain Candy: Boring but Important. In studies of more than 2,000 people, a purpose beyond the self, like wanting to make a difference for others, helped people stick with dull but important tasks. Source: A purpose beyond the self.
Growing evidenceThe research
  1. Yeager, D. S., Henderson, M. D., Paunesku, D., Walton, G. M., D’Mello, S., Spitzer, B. J., & Duckworth, A. L. (2014). Boring but important: A self-transcendent purpose for learning fosters academic self-regulation. Journal of Personality and Social Psychology, 107(4), 559–580.
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Giant Brain Candy: The Unwritten Memorial. In Pericles’ funeral speech, as Thucydides wrote it some 2,400 years ago, the fallen are remembered not only by inscribed stones but by an unwritten memorial in people’s hearts. Source: Pericles’ funeral oration.
Guiding wisdomThe research
  1. Thucydides. (n.d.). The history of the Peloponnesian War, Book 2 (R. Crawley, Trans.). The Internet Classics Archive, MIT. (Original work written c. 400 BCE)
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The Legacy Deep Dive: the research, seminar by seminar →