id,claim,popular_number,where_repeated,traced_origin,origin_year,best_evidence,best_estimate,verdict,journal_articles_repeating,openalex_search,key_sources,checked_on
thoughts,"We have 60,000 to 70,000 thoughts a day","60,000 or 70,000 (also 50,000 to 80,000; often ""and 80% are negative"" or ""95% repeat"")","Self-help and business pages for two decades: the Chopra Center (60,000 to 80,000, 2007), a Forbes column (2012), a university neuroimaging lab's ""Brain Trivia"" page (70,000) and an opinion piece in The Straits Times in 2024.","No source has ever been produced. An undated sales-coaching page credits the ""National Science Foundation"" with 12,000 to 50,000 thoughts; the NSF article it describes has never been found. The 2012 Forbes column credited a Stanford researcher, who replied that he had no idea where the quote came from.",2003 or earlier,"Tseng and Poppenk scanned 184 young adults (7-tesla MRI, Human Connectome Project) while they watched films and rested, and counted each shift of brain activity into a new stable pattern as a new thought. The median was about 6.5 shifts a minute; with 8 hours of sleep, the paper estimates ""over six thousand daily thoughts""; the university's press release said about 6,200. It is one method in young adults, not a census of the mind.","About 6,200 a day (one 2020 brain-scan estimate in young adults)",No traceable source,31,"""60,000 thoughts"" OR ""70,000 thoughts"" OR ""60000 thoughts"" OR ""70000 thoughts"" OR ""50,000 thoughts"" OR ""80,000 thoughts""",10.1038/s41467-020-17255-9,2026-10-22
decisions,"Adults make 35,000 decisions a day","35,000 (""remotely conscious decisions""; a child 3,000)","CNN Health in 2022, crediting a University of Leicester lecturer whose 2018 Psychology Today post had itself questioned how the number was derived. It also runs through leadership and productivity writing.","The earliest dated copy is a Roberts Wesleyan College blog post of March 2015, which says ""various internet sources"" estimate 35,000. A book citation was added to the post later; a reader who checked the book found no such number in it.",2015,"Wansink and Sobal (2007) asked people how many food decisions they make. Asked directly, people said about 14; adding up their answers meal by meal gave 226.7, which became the ""200 food decisions"" figure. A 2025 paper argues the jump is an artefact of asking in parts. The paper now carries an expression of concern dated 17 March 2026.",No count exists; 227 food decisions in a 2007 study now under an expression of concern,No traceable source,33,"""35,000 decisions"" OR ""35000 decisions"" OR ""35,000 choices"" OR ""35,000 remotely conscious""",10.1177/0013916506295573; 10.1177/00139165261429708; 10.1016/j.appet.2025.107928,2026-10-22
goldfish,"Our attention span is 8 seconds, shorter than a goldfish's","8 seconds (12 in 2000), against 9 seconds for a goldfish","Time (""You now have a shorter attention span than a goldfish"", 2015), and, by the BBC's count, the Telegraph, the Guardian, USA Today, the New York Times and others.","Statistic Brain's ""Attention Span Statistics"" page, first archived in February 2012, gave 12 seconds for 2000, 8 seconds for 2012 and 9 seconds for a goldfish, citing the Associated Press. Microsoft Canada's 2015 ""Attention spans"" report reprinted the numbers on page 6 as ""Source: Statistic brain""; its own research, a survey of 2,000 Canadians and a brain-recording (EEG) study of 112 people, measured kinds of attention, not a span in seconds.",2012,"Attention depends on the task, so there is no single span to measure. The closest real measurements are how long office workers stay with one thing before switching: 2 minutes 11 seconds on any device or paper document in 2004 field work, and an average of 47 seconds on one computer screen (median 40) in 40 workers in 2016. That is switching between windows, not an inability to concentrate. Goldfish have been used for decades to study learning and memory, retested a day or two weeks after training.",No single attention span exists; workers switch screens every 47 seconds on average,No traceable source,73,"goldfish AND ""attention span"" AND (""8 seconds"" OR ""eight seconds"" OR ""8-second"" OR ""9 seconds"" OR ""nine seconds"")",10.1145/2858036.2858202; 10.1145/985692.985707,2026-10-22
refocus,It takes 23 minutes to refocus after an interruption,23 minutes (23 minutes and 15 seconds),"Productivity apps and business media; the exact ""23 minutes and 15 seconds"" comes from a 2008 Fast Company interview. Mark's own 2015 paper summarised the study as ""around 23 minutes"".","Mark, Gonzalez and Harris (2005) shadowed 24 information workers, each for about three and a half working days. When interrupted work was resumed the same day, the average gap was 25 min 26 s (standard deviation 54 min 48 s): 22 min 37 s after an outside interruption, 29 min 1 s after a self-interruption. The 23 min 15 s first appears in the 2008 interview; it is not in the published papers.",2008,"In the 2005 study, people worked on about two other projects before returning, so the 25 minutes includes other work. A 2008 lab experiment found interrupted people finished tasks slightly faster but reported more stress. In 2023 Mark herself gave the figure as about 25 and a half minutes. More on switching tasks: does multitasking lower your IQ?","25 min 26 s until people returned to interrupted work, after about two other tasks (24 workers, 2005)",Partly true,27,"""23 minutes and 15 seconds"" OR (""23 minutes"" AND ""Gloria Mark"") OR ((""23 minutes to get back"" OR ""23 minutes to refocus"" OR ""23 minutes to return"" OR ""23 minutes to regain"" OR ""23 minutes to resume"") AND (interruption OR distraction))",10.1145/1054972.1055017,2026-10-22
images,"The brain processes images 60,000 times faster than text","60,000 times faster (often with ""90% of information sent to the brain is visual"")","Marketing, e-learning and infographic advice, 3M's own guide (""we can process visuals 60,000 times faster than text""), and a 2024 arXiv review of visual AI. It is the unsourced number research papers repeat most: 140 journal articles in our count.","Alan Levine traced it to a 28 June 1982 Business Week advertising section, in a statement by the president of Computer Pictures Corporation. 3M repeated it as a finding of unnamed ""behavioral research"". The 1986 University of Minnesota and 3M study found visual aids made a talk 43% more persuasive; its lead author later told Levine his research ""had nothing to do with visual processing speed"". Jon Schwabish found that 3M's own report gave the number with no citation.",1982,"People can grasp the gist of a picture shown for 13 milliseconds and brain activity tells photos with an animal from photos without one about 150 milliseconds after they appear. Adults read about 238 words a minute, about a quarter of a second a word. The tasks differ, so no honest ratio exists, but nothing measured comes near 60,000.","No ratio measured; a picture's gist in 13 ms, a word read in about 250 ms",No traceable source,140,"(""60,000 times faster"" OR ""60000 times faster"" OR ""60,000 times quicker"") AND text",10.3758/s13414-013-0605-z; 10.1038/381520a0; 10.1016/j.jml.2019.104047,2026-10-22
bits,The senses take in 11 million bits a second; the conscious mind handles 40,"11 million bits a second in, 40 or 50 (sometimes 10) bits a second conscious","Books on the unconscious mind, management readers and teacher training, for example in a 2015-16 American Educator article on implicit bias.","Information-theory estimates of the senses' channel capacity by Kupfmuller (1959) and Zimmermann (in German and US physiology textbooks of the 1980s), popularised by Tor Norretranders' book ""The User Illusion"", which put the senses at over 11 million bits a second and consciousness at about 50 bits a second or less. Other retellings give 40, 16 or ""a few dozen"".",1986,"Zheng and Meister (2025) estimate human behavioural throughput at about 10 bits a second, from typing, speech, memory sports and games, against about a billion bits a second gathered by the senses. The gap is roughly a hundred million times, larger than the popular version suggests.",About 10 bits a second of thought and action against about a billion bits of sensory input (2025),Partly true,56,"""11 million bits"" OR ""11,000,000 bits"" OR ""eleven million bits""",10.1016/j.neuron.2024.11.008,2026-10-22
forgetting,We forget 70% of what we learn within 24 hours,"50% within an hour, 70% within 24 hours, 90% within a week","Corporate training and e-learning pages, such as TalentLMS (2023). The 50/70/90 version appears in a 2014 Learning Solutions column with no study cited.","Ebbinghaus learned 13-syllable nonsense lists and relearned them after 20 minutes to 31 days. After a day his saving was 33.7%, so 66.3% of the first learning time was needed again. A 2010 review of 14 studies found forgetting ranged from 0% to 94% depending on the material and the method.",1885,"Murre and Dros (2015) repeated the experiment with one person over 70 hours of learning and got a similar curve, with a small upward jump at one day, possibly sleep. For meaningful material, how much is forgotten depends on the material, how it was learned and how memory is tested. More on memory: memory and IQ.","One man, nonsense syllables: relearning a day later took 34% less time (1885; replicated 2015)",Partly true,11,"(""forgetting curve"" OR Ebbinghaus) AND (""forget 70%"" OR ""forget about 70%"" OR ""forget approximately 70%"" OR ""forget up to 70%"" OR ""forget an average of 70%"" OR ""forgotten 70%"" OR ""forget 70 percent"" OR ""70% within 24 hours"" OR ""70 percent within 24 hours"" OR ""70% in 24 hours"" OR ""70% of new information"" OR ""70% of what they learn"" OR ""70% of what they have learned"" OR ""70% of what was learned"")",10.1371/journal.pone.0120644,2026-10-22
neurons,The human brain has 100 billion neurons,100 billion (now often 86 billion),"Textbooks, museum displays and science writing for half a century, and still in research: 1,378 journal articles in our count, more than twice the 609 that give 86 billion.",For half a century the brain was said to hold about 100 billion neurons and ten times as many glial cells. A 2016 review of 150 years of cell counting traced how these round numbers spread. Until 2009 the total had not been counted: the paper that did it noted the widely quoted 100 billion while the actual number remained unknown.,1991 (textbooks),"Azevedo and colleagues (2009) dissolved whole brains into a suspension of cell nuclei and counted the neurons (the ""isotropic fractionator""): 86.1 plus or minus 8.1 billion neurons and 84.6 billion other cells, in four men. The same method found 67.3 billion in five older women without dementia. Goriely (2025) argues the honest answer is a range, roughly 61 to 99 billion; Roberto Lent, a co-author of the 2009 count, replied in the same journal that the brain has ""around 86 billion neurons"". Brain size and IQ: what the correlation really is.",86.1 billion in 4 men (2009); 67.3 billion in 5 older women (2013),Partly true,1378,"""100 billion neurons"" OR ""100,000,000,000 neurons"" OR ""hundred billion neurons"" OR ""100 billion nerve cells""",10.1002/cne.21974; 10.1093/brain/awt273; 10.1093/brain/awae390,2026-10-22
energy,The brain uses 20% of the body's energy,20% (while it is about 2% of body weight),"Everywhere from textbooks to health sites, and in 564 journal articles in our count, more than any other number here except the 100 billion neurons.","Physiology measurements of the brain's oxygen and glucose use going back to the mid-20th century, summarised by Raichle and Gusnard (2002).",mid-20th century,"Kuzawa and colleagues (2014) combined PET and MRI data from birth to adulthood. The brain's glucose use equals 52.5% (boys) and 59.8% (girls) of the body's resting energy at birth, peaks at 66.3% and 65.0% at about 4 years, and falls to 19.1% and 24.0% in young adults. As a share of all the energy used in a day, the adult brain takes 10.9% (men) and 15.0% (women). The authors link the childhood peak to the slow body growth of human children.","About 20% of resting energy in adults (19% men, 24% women); about 66% at age 4",Supported,564,"""20% of the body's energy"" OR ""20 percent of the body's energy"" OR ""20% of the body's oxygen"" OR ""20 percent of the body's oxygen"" OR ""20% of the body's total energy"" OR ""20% of the body's metabolic""",10.1073/pnas.172399499; 10.1073/pnas.1323099111,2026-10-22
water-fat,The brain is 75% water and 60% fat,"75% (or 73%, 80%) water; 60% fat, ""the fattest organ""","Guinness World Records calls the brain the ""fattiest organ"", ""typically composed of 60% fat""; Live Science (2021); nutrition and supplement pages.","Water: a 1945 chemical analysis of one man's body found the brain, spinal cord and nerves were 73.3% water, a figure the US Geological Survey later popularised. Fat: in 1965 O'Brien and Sampson measured lipids at 36% to 40% of the dry weight of grey matter and 49% to 66% of white matter. A 2009 review began its abstract with ""nearly 60 percent fat"", without the qualifier.",1945 (water); 1965 (fat),"An MRI study of 21 adults measured 83.7% water in grey matter and 69.1% in white matter. Once the water in O'Brien and Sampson's samples is counted, fat is 5% to 7% of grey matter and 9% to 16% of white matter by weight (our arithmetic from their Table 1); the 1945 analysis gave 12.7% ether extract (mostly fat) for brain, spinal cord and nerves. Stated correctly, the brain is ""nearly 60% lipid by dry weight"".","Water 70-85% (grey matter more); fat about 5-16% of living tissue, about 60% of dry weight",Partly true,44,"""brain is 75% water"" OR ""brain is about 75% water"" OR ""brain is approximately 75% water"" OR ""brain is 73% water"" OR ""brain is 80% water"" OR ""brain is 75 percent water"" OR ""brain is made up of 75% water"" + ""brain is 60% fat"" OR ""brain is nearly 60% fat"" OR ""brain is about 60% fat"" OR ""brain is approximately 60% fat"" OR ""60% of the brain is fat"" OR ""brain is made up of 60% fat"" OR ""brain is 60 percent fat"" OR ""brain is nearly 60 percent fat""",10.1016/S0022-2275(20)39619-X; 10.1016/S0021-9258(19)51339-4; 10.3389/fneur.2019.01333,2026-10-22
age-five,90% of the brain develops by age 5,90% of brain development (or growth) happens before age 5,"Early-childhood campaigns and university pages: First Things First in Arizona (""90% of a child's brain develops by age 5""), a University of Connecticut trivia post in 2025 and Discover (2022).","The earliest dated use we found is a 2014 Robert Wood Johnson Foundation report: ""90 percent of a child's brain capacity is developed by age 5"", with no study cited. The Royal College of Physicians and Surgeons of Canada repeated it later that year, citing that report. First Things First explained it as size: about 80% of adult size by age 3 and 90% by age 5.",2014,"Brain volume is about 35% of adult size a few weeks after birth and about 80% by age 2, and ""already at 95% of its peak size by age 6"". Growth in size is not the end of development: white matter keeps growing until about 29, and the brain's long-range connections keep maturing after adolescence. A related number was corrected at its source: the Harvard Center on the Developing Child, which had said ""700 to 1,000 new neural connections form every second"", now says more than a million, a change it made in 2017.",About 90-95% of peak brain size by about age 6; development continues for decades,Partly true,107,"""90% of brain development"" OR ""90% of brain growth"" OR ""90% of a child's brain"" OR ""90 percent of brain development"" OR ""90 percent of brain growth"" OR ""90% of the brain develops"" OR ""90 percent of a child's brain""",10.1016/j.neuron.2010.08.040; 10.1038/nrn.2018.1; 10.1038/s41586-022-04554-y,2026-10-22
age-25,The brain is fully developed at 25,"25 (the prefrontal cortex ""finishes"" at 25)","News, parenting and legal writing since 2005, and a 2013 review paper that called maturation ""fully accomplished at the age of 25"".","The landmark NIH scans of children stopped at age 21. In 2004 the lead researcher told Time that, to follow volunteers until the brain settled, ""we'd probably go to age 25"". By 2005 a Washington Post story said the brain region ""is not fully formed until age 25"". In 2009 the same researcher wrote that the brain matures ""well into the 20s"".",2004,"Brain charts built from 123,984 scans of 101,457 people show different parts peaking at very different ages: grey matter volume at about 6, white matter at about 29. Mousley and colleagues (2025) found turning points in brain wiring at about 9, 32, 66 and 83, estimated on the 3,802 people with typical development among the 4,216 scanned. When thinking skills peak is a separate question: see at what age is your brain sharpest?","No single age: grey matter peaks near 6, white matter near 29; wiring changes again at about 32",Partly true,116,"""fully developed until age 25"" OR ""fully developed until the age of 25"" OR ""fully developed until about age 25"" OR ""fully developed until around age 25"" OR ""fully developed until approximately age 25"" OR ""fully developed until the mid-20s"" OR ""fully mature until age 25"" OR ""fully mature until the age of 25"" OR ""fully mature until about age 25"" OR ""fully mature until the mid-20s"" OR ""fully developed by age 25"" OR ""fully developed at age 25"" OR ""fully mature at age 25"" OR ""fully matures at age 25"" OR ""fully matures around age 25"" OR ""fully mature by age 25"" OR ""fully developed by the age of 25"" OR ""fully mature by the age of 25""",10.1038/s41467-025-65974-8; 10.1038/s41586-022-04554-y,2026-10-22