Gauge
One quirk of the mind at a time: is the next one more or less common than the last? Keep the streak alive. Every number is real and sourced. A fresh set every day.
Run 0 · best 0
Is this more or less common?
?%
How common is it? Compare the two. (Keys: ↑ / ↓)
0in a row
You're bad at this on purpose, everyone is. We're wired to guess how common something is from how easily an example springs to mind, not from real numbers, the “availability” shortcut. So vivid, memorable quirks feel far more widespread than they are, and quiet ones vanish. The only cure is the boring one: look it up. Every figure here is sourced below.
Our sources
// every fact this game reveals was checked before it went up
✓ Shown a round shape and a spiky shape, about 95% of people match the round one to the word 'bouba', one of psychology's most reliable cross-cultural findings.
, Ramachandran & Hubbard, 2001; Ćwiek et al., Phil. Trans. R. Soc. B, 2022
✓ In Svenson's 1981 study, 93% of the US sample rated themselves in the top half of drivers for skill, and 88% for safety, impossible for more than about half of any group.
, Svenson, 'Are we all less risky and more skillful than our fellow drivers?', Acta Psychologica, 1981
≈ Reviews estimate that roughly two-thirds of people (about 60 to 70%) report having experienced déjà vu at least once in their lives.
, Brown, 'A review of the déjà vu experience,' Psychological Bulletin, 2003
✓ In a survey of over 4,000 people, about 21% reported the 'visual ear', hearing a faint sound when watching silent motion such as a skipping-pylon GIF.
, Fassnidge & Freeman, 'Sounds from seeing silent motion,' Cortex, 2018
✓ About 10% of people are left-handed; a large meta-analysis put the figure at roughly 10.6%, a proportion that has stayed broadly stable across populations.
, Papadatou-Pastou et al., 'Human handedness: A meta-analysis,' Psychological Bulletin, 2020 (~10.6%)
✓ A meta-analysis estimates that about 8% of the general population (7.6%) has experienced sleep paralysis at least once, with much higher rates among students and psychiatric groups.
, Sharpless & Barber, 'Lifetime prevalence rates of sleep paralysis,' Sleep Medicine Reviews, 2011 (7.6% general population)
✓ Classic synaesthesia, where senses cross, such as seeing letters in colour, occurs in roughly 4% of people (about 4.4% in a large random-sample study).
, Simner et al., 'Synaesthesia: The prevalence of atypical cross-modal experiences,' Perception, 2006 (4.4%)
≈ Aphantasia, the absence of a voluntary 'mind's eye', is estimated to affect on the order of 1% of people for complete aphantasia (with somewhat higher rates for near-absent imagery).
, Dance, Ipser & Simner, 'The prevalence of aphantasia (imagery weakness) in the general population,' Consciousness and Cognition, 2022
≈ Earworms (a tune stuck in the head) are near-universal: in a large study the great majority of people reported experiencing them regularly, most at least once a week.
, Beaman & Williams, 'Earworms: A phenomenological investigation,' British Journal of Psychology, 2010
≈ The 'phantom vibration' (feeling a phone buzz that didn't) is very common: a study of medical staff found about 68% had experienced it, with other samples reporting figures in a similar range.
, Rothberg et al., 'Phantom vibration syndrome among medical staff,' BMJ, 2010 (~68%)
≈ The 'high place phenomenon', a sudden urge to jump when at a safe height, was reported by roughly half of participants in a university study, and was linked to sensitivity to internal cues rather than to a wish to die.
, Hames, Ribeiro, Smith & Joiner, 'An urge to jump affirms the urge to live,' Journal of Affective Disorders, 2012
≈ Brain freeze (cold-stimulus headache) is common, with prevalence estimates broadly in the region of a third of people, varying widely by how it is measured and the population studied.
, Hulihan, 'Ice cream headache,' BMJ, 1997; Mages et al. on cold-stimulus headache prevalence
≈ The photic sneeze reflex (sneezing on stepping into bright light) is an inherited trait affecting an estimated 18 to 35% of people.
, Breitenbach et al., 'The photic sneeze reflex as a risk factor to cataract surgery,' 1993; reviews of the ACHOO syndrome
≈ Misophonia (strong aversion or anger toward specific sounds such as chewing) shows clinically significant symptoms in roughly a fifth of people in recent general-population studies.
, Wu et al., 2014; Jakubovski et al., 'Prevalence and clinical correlates of misophonia symptoms,' 2022 (~1 in 5)
✓ Natural red hair is the rarest human hair colour, occurring in only about 1 to 2% of the global population, driven mainly by recessive variants of the MC1R gene.
, Standard human-genetics references on MC1R and red hair prevalence (~1 to 2% globally)