Mark ở vũ trụ khácVIMark học AI
Mark ở vũ trụ khác · Another Universe Common Myths #6 · Expertise · Tracing the source

10,000 hours and you're an expert?

10,000 hours ?

From a study of 30 violin students in Berlin (1993) to the "rule" in the bestseller Outliers (2008)

The mythput in 10,000 hours of practice and you become an expert, in anything
The real originthe average of the best violin students at age 20
Made famous byMalcolm Gladwell, Outliers, 2008
Verdictthe right practice is necessary, but there is no magic number
Review in 1 minute

Essentials

It is an average~10,000 hours was the average of the best violin students at age 20, not a finish line.
An 8-fold spreadChess players reached master level after anywhere from about 3,000 to over 23,000 hours.
The kind of hour mattersDeliberate practice: a narrow goal, fast feedback, just beyond your comfort zone.
Part of the storyPractice explains roughly 1/5 to 1/3 of the differences in chess, music and sport. Far less in office work.
Don't swap one myth for anotherThe rest is not automatically "innate talent". Practice still matters.

Sources: Ericsson, Krampe and Tesch-Römer (Psychological Review, 1993); Ericsson and Pool, Peak (2016); Campitelli and Gobet (2011); Macnamara, Hambrick and Oswald (Psychological Science, 2014); Hambrick et al. (Intelligence, 2014).

Part 1

The question behind the myth

A small study of violin students became the "10,000-hour rule" for every profession. The real question is not "how many hours" but "what kind of hours, and how much do hours explain".

1993A findingThe best violin students had practised alone for far more hours than weaker ones.
→
2008A ruleOutliers names it the "10,000-Hour Rule", with stories about the Beatles and Bill Gates.
→
2014–2019A correctionMeta-analyses and a replication: practice matters, but less than people think.
Part 2

Where the myth came from

Every retelling dropped one more condition.

The claim across four retellings. 1993, Ericsson: the best violin group averaged about 10,000 hours of deliberate practice by age 20. 2006, Levitin: 10,000 hours are needed to become a world-class expert, in anything. 2008, Gladwell: the 10,000-hour rule. Today online: put in 10,000 hours and you are an expert. Conditions lost along the way: average, best group, deliberate practice, violin only. 1993 · Ericsson "average""best group""deliberate practice""violin, age 20" 2006 · Levitin "10,000 hoursare required""world-class expert,in anything" 2008 · Gladwell "the 10,000-hour rule"Beatles, Bill Gates today · social media "do 10,000 hoursand you're an expert" Lost with each retelling: "average" "best group" "deliberate practice" "violin only"
Nobody lied; the conditions just got trimmed. Ericsson later wrote that 10,000 was a round number, that 7,400 hours at age 18 would have done just as well, and that at that age these students were still far from being masters.Sources: Ericsson, Krampe and Tesch-Römer (1993); Levitin, This Is Your Brain on Music (2006), quoted by Gladwell in Outliers (2008), chapter 2; Ericsson and Pool, Peak (2016) and their Salon article (10 April 2016), read via secondary quotations.
1973 · Simon and Chase, chessA master needs about a decade. A master was estimated to have spent 10,000 to 50,000 hours "staring at chess positions". This is the distant root of the "ten years" idea.
1993 · Ericsson, Krampe and Tesch-Römer, Berlin30 violin students, 3 groups. The best group had practised alone the most. The paper called this "deliberate practice".
2006 · Daniel LevitinIn This Is Your Brain on Music: "ten thousand hours of practice" are required for world-class mastery, "in anything".
2008 · Malcolm Gladwell, OutliersChapter 2 is titled "The 10,000-Hour Rule". The Beatles playing in Hamburg, Bill Gates on a computer as a schoolboy.
2013 · Gladwell answers his criticsIn The New Yorker: the rule is about complex fields and does not promise that anyone can become an expert.
2016 · Ericsson and Pool, PeakThe author of the original study says the "10,000-hour rule" gets his work wrong in several ways.

Sources: Simon and Chase, American Scientist 61(4), 1973 (the 10,000–50,000 hours figure as quoted in Gladwell, The New Yorker, 2013, secondary source); Ericsson et al. (1993); Levitin (2006); Gladwell (2008, 2013); Ericsson and Pool (2016).

Part 1

Where it came from

Berlin violinistsLevitinOutliersThe Beatles
Part 2

What the evidence says

3,016–23,608 hoursmeta-analyses2019 replicationfact check
Part 3

Work lesson

narrow goalsfast feedbackoutside the comfort zoneMark's score
Part 3

What the evidence says

The original study: hours rise with skill level

Ericsson, Krampe & Tesch-Römer 1993Psychological Review 100(3)
Accumulated hours of solitary practice up to age 18, as estimated by the students themselves. Best group: 7,410 hours. Good group: 5,301 hours. Future music teachers: 3,420 hours. At age 20, the best group averaged about 10,000 hours. best7,410 h good5,301 h future teachers3,420 h ~10,000 h: best group, at age 20 solitary practice accumulated up to age 18 (self-estimated)
This is an average, and hours are recalled. Each student estimated their weekly practice for every year since they started playing. Ericsson notes that many in the best group had not reached 10,000 hours by 20.Sources: Ericsson, Krampe and Tesch-Römer (1993), study 1 (30 students); the 7,410 / 5,301 / 3,420 hour figures read via secondary summaries (Macmillan Learning; notes on Talent Is Overrated), some sources give 5,310 or 3,240 instead; the ~10,000 hours at 20: Ericsson and Pool (2016).

Chess: same destination, an 8-fold spread in hours

Gobet & Campitelli 2007Developmental Psychology 43(1)
104 Argentinian chess players. Practice hours needed to reach master level: fastest 3,016, average 11,053, slowest 23,608. Some players had practised over 25,000 hours without reaching master level. 05,00010,00015,00020,00025,000 h 3,016fastest 11,053average 23,608slowest "10,000 hours" >25,000, not yet each dot: hours until reaching master title
Lots of practice is necessary, but not sufficient. Nobody reached master level with very little practice, yet at the same number of hours one player had arrived and another had not.Sources: Gobet and Campitelli, Developmental Psychology 43(1), 2007 (104 players); the 3,016 / 11,053 / 23,608 / >25,000 hour figures from the review by Campitelli and Gobet, "Deliberate practice: necessary but not sufficient", Current Directions in Psychological Science 20(5), 2011.

Meta-analysis: how much of the difference do hours explain

variance explainedMacnamara et al. 2014
Share of differences in performance explained by deliberate practice, by domain. Games such as chess: 26%. Music: 21%. Sports: 18%. Education: 4%. Professions: under 1%. Overall about 12%. 26%games (chess) 21%music 18%sports 4%education <1%professions 88 studies, over 11,000 people · about 12% overall the rest: starting age, memory, personality, good teachers, environment, luck, and measurement error
Practice really helps, but it is only part of it. The effect was weaker when practice was logged in diaries rather than recalled. "Professions" here covers programming, football refereeing, insurance sales and piloting.Sources: Macnamara, Hambrick and Oswald, Psychological Science 25(8), 2014, pp. 1608–1618; Association for Psychological Science press release (July 2014) for the ~12% overall figure.

Higher estimates

Correcting for measurement error, practice explains about 34% in chess and 30% in music (Hambrick et al., Intelligence, 2014).

Pushback

Ericsson argued that Macnamara's team included activities that are not deliberate practice, pulling the figure down. Platz et al. (2014) found a correlation of 0.61 in music.

Elite sport

18% of differences across sport overall, but among world-class athletes practice explains almost nothing (about 1%).

Sources: Hambrick, Oswald, Altmann, Meinz, Gobet and Campitelli, Intelligence 45, 2014; Platz, Kopiez, Lehmann and Wolf, Frontiers in Psychology, 2014; Macnamara, Moreau and Hambrick, Perspectives on Psychological Science 11(3), 2016 (18%); the ~1% figure for elite athletes per BPS Research Digest and Fox News (2016), secondary sources.

Re-running the Berlin study in 2019

replicationMacnamara and Maitra 2019
A 2019 replication with 39 violinists, double-blind. The good group estimated about 9,844 hours of practice, the best group about 8,224. The difference was not statistically significant. The core 1993 finding did not replicate. best~8,224 h good~9,844 h 39 people · raters did not know the hoursdifference not statistically significant (p = 0.364)
This time the best group did not practise more than the good group. Practice was still related to skill across the whole sample, but much more weakly than in 1993. It is a small study of one instrument, so not the last word.Sources: Macnamara and Maitra, Royal Society Open Science 6: 190327, 2019; group hours read via a secondary report (The Strad, 2019).

Years on the job do not turn into practice

experience ≠ practiceChoudhry et al. 2005
A review of 62 evaluations of doctors: 52% found quality decreased with years in practice on every measure, 21% decreased on some measures, 21% found no association, and only 2% found improvement on every measure. 52% worse on all measures 21% partly worse 21% no change 2% better 62 evaluations of the link between years in practice and quality of care last grey block: evaluations with other results
Repeating what you already do well does not make you better. Ericsson calls this the difference between "doing" and "practising": once a task is automatic, more hours of it no longer push skill up.Sources: Choudhry, Fletcher and Soumerai, Annals of Internal Medicine 142(4), 2005, pp. 260–273 (32/62 = 52%; 13/62 = 21%; 13/62 = 21%; 1/62 = 2%); Ericsson and Pool, Peak (2016).

Deliberate practice is not just "time spent practising"

deliberate practiceEricsson and Pool 2016, chapter 1
The deliberate practice loop has four steps: a narrow, measurable goal; full focus; immediate feedback; adjust and raise the difficulty a little, outside the comfort zone. Then repeat. 1 · narrow, measurable goal 2 · full focus 3 · immediate feedback 4 · adjust, a bit harderoutside the comfort zone
The four features of "purposeful practice". Ericsson adds one condition for it to count as deliberate practice: a teacher or a proven method from that field. The 1993 paper describes this kind of practice as effortful and "not inherently enjoyable".Sources: Ericsson and Pool, Peak (2016), chapters 1 and 4; Ericsson, Krampe and Tesch-Römer (1993).
Part 4

Fact check: Solid, Caution, Wrong

11 common versions of the myth, checked against the original research. Click a line to see why.

SOLIDThe very best have usually practised for many years

In violin (Ericsson 1993) and chess (Gobet and Campitelli 2007), nobody reached the top with very little practice. The fastest of 104 Argentinian players still needed about 3,000 hours.

SOLIDThe kind of practice matters more than the hours that pass

This is Ericsson's central point from 1993 to Peak (2016): narrow goals, feedback, slightly beyond your ability. The review of doctors (Choudhry 2005) shows that years on the job do not automatically make people better.

SOLIDPractice explains a sizeable share of differences in chess, music and sport

About 18–26% according to Macnamara (2014), 30–34% when corrected for measurement error (Hambrick 2014). Not small, but not everything.

CAUTION"It takes about 10,000 hours to become an expert"

The number has a real origin: the average of the best violin group at age 20. But it is an average, recalled from memory, and at that age they were not yet masters. In chess, hours to master level differ almost 8-fold (3,016 to 23,608).

CAUTION"Practice explains only 12%, so it hardly matters"

The 12% is an average across many domains and measures. Ericsson disputed the definition used in that analysis; correcting for measurement error gives higher shares. The sources still disagree, but nobody says practice is useless.

CAUTION"The Beatles succeeded thanks to 10,000 hours in Hamburg"

They did play a great deal. But Ericsson argues that nightly performing is not deliberate practice, and that Gladwell did not distinguish the two. An anecdote cannot prove a rule.

CAUTION"So innate talent decides everything"

That swaps one myth for another. The unexplained part includes starting age, working memory, personality, quality of teaching, environment and measurement error, not just genes. Gobet and Campitelli: practice is "necessary but not sufficient".

WRONG"Anyone who puts in 10,000 hours becomes an expert"

In the Argentinian chess sample, some players had practised more than 25,000 hours without reaching master level (Campitelli and Gobet 2011). The 2019 replication also found the best group did not practise more than the good group.

WRONG"The 10,000 figure holds for every field"

Ericsson says the number varies from field to field. In professions, practice explained under 1% of differences, in education 4% (Macnamara 2014).

WRONG"Ericsson came up with the 10,000-hour rule"

The name is Gladwell's (2008). Ericsson later wrote that the rule misrepresents his research in several ways (Peak, 2016; Salon, 2016).

WRONG"Doing a job for 10 years means 10,000 hours of practice"

Routine hours on the job are not deliberate practice. 32 of 62 evaluations of doctors found quality declined with years in practice (Choudhry 2005).

Sources: as in Part 3 and the list in Part 8. Ericsson's point that "performing is not deliberate practice" read via interviews and secondary quotations (Wharton Knowledge, Salon 2016).

Part 5

Verdict on the myth

Scores are Mark's assessment based on the sources in Part 8, not figures from a study. Higher means more wrong, more persistent, more harmful.

How wrong
3/5
How persistent
5/5
How harmful
2/5
The grain of truth
  • The top takes many years of practice
  • Encourages persistence instead of blaming "natural gifts"
  • Brought deliberate practice to a wide audience
What's wrong and harmful
  • Turns an average into a finish line
  • Makes people count hours instead of measuring progress
  • Easy to blame "not enough hours" when someone stalls

Half right: the right practice is necessary, but there is no magic number, and not every hour is equal.

More: why this myth lives on

A round number, a fair-sounding promise ("anyone can do it"), and great stories about the Beatles and Bill Gates. It is easier to remember than "deliberate practice explains a sizeable but not complete share of differences in performance, depending on the field".

Both sides of the debate agree on one thing: practice helps. They differ on how big its share is and how to measure it.

Part 6

Work lesson: measure progress, don't count hours

For any skill at work: presenting, writing emails, Excel, client interviews, coding.

A week of deliberate practice. Monday: pick one sub-skill and one measurable criterion. Tuesday and Thursday: two 30-minute sessions on the weakest spot. Right after each session: get feedback, record yourself or ask a colleague to score against a checklist. Friday: compare with last week, and if you hit it, make it a little harder. Monday · go narrow1 sub-skill"a 30-second talk opening"+ 1 measurable criterion Tue, Thu · practise2 sessions × 30 minonly the weakest spotnotifications off Right after · feedbackrecord, checklistor ask 1 person to scoresame day, not next quarter Friday · compare, raisevs last weekhit it? make ita bit harder Log progress, not hours. A comfortable hour is worth less than 30 minutes just past your limit.
Each step is one feature of deliberate practice. Narrow goal, focus, fast feedback, and leaving the comfort zone. The number of sessions and minutes are Mark's suggestion, not figures from research.
Break the skill downDon't practise "being good at Excel". Practise "building a summary table from raw data in 10 minutes".
Shorten the feedback loopAt work, feedback comes late or never. Make your own: record yourself, compare with a model, ask someone to score.
A stretch, not an overloadIf it feels easy, you've stopped improving. If it feels hopeless, it's too hard. Aim for "only with effort".
Compare with yourselfHours don't explain all the differences. Don't beat yourself up because someone else improves faster; check whether you beat last week.
Deliberate practice: necessary but not sufficient.Title of the review by Guillermo Campitelli and Fernand Gobet, Current Directions in Psychological Science (2011).
Part 7

Further reading

Anders Ericsson and Robert Pool, Peak (2016)The author of the original study explains deliberate practice and why the "10,000-hour rule" is wrong.
Malcolm Gladwell, Outliers (2008), chapter 2Read it to see how well the myth is told, then compare it with the evidence section.
David Epstein, The Sports Gene (2013)The other side of the debate: the role of physical and genetic differences in sport.
Common Myths #7: "Our attention span is now shorter than a goldfish's"Where the "8 seconds" figure (linked to a 2015 Microsoft Canada report) came from, and why to check viral numbers before putting them on a slide.
Part 8

Sources

Original papers first. Where only a secondary source was available, it is labelled next to the number.

  1. K. A. Ericsson, R. T. Krampe and C. Tesch-Römer, "The Role of Deliberate Practice in the Acquisition of Expert Performance", Psychological Review 100(3), 363–406, 1993.
  2. H. A. Simon and W. G. Chase, "Skill in Chess", American Scientist 61(4), 1973.
  3. D. Levitin, This Is Your Brain on Music, 2006.
  4. M. Gladwell, Outliers: The Story of Success, 2008, chapter 2; "Complexity and the Ten-Thousand-Hour Rule", The New Yorker, August 2013.
  5. B. N. Macnamara, D. Z. Hambrick and F. L. Oswald, "Deliberate Practice and Performance in Music, Games, Sports, Education, and Professions: A Meta-Analysis", Psychological Science 25(8), 1608–1618, 2014. APS press release
  6. D. Z. Hambrick et al., "Deliberate practice: Is that all it takes to become an expert?", Intelligence 45, 34–45, 2014.
  7. F. Platz, R. Kopiez, A. C. Lehmann and A. Wolf, "The influence of deliberate practice on musical achievement: a meta-analysis", Frontiers in Psychology 5, 2014. frontiersin.org
  8. F. Gobet and G. Campitelli, "The role of domain-specific practice, handedness, and starting age in chess", Developmental Psychology 43(1), 159–172, 2007; G. Campitelli and F. Gobet, "Deliberate practice: Necessary but not sufficient", Current Directions in Psychological Science 20(5), 280–285, 2011.
  9. B. N. Macnamara, D. Moreau and D. Z. Hambrick, "The Relationship Between Deliberate Practice and Performance in Sports: A Meta-Analysis", Perspectives on Psychological Science 11(3), 333–350, 2016. BPS Research Digest
  10. B. N. Macnamara and M. Maitra, "The role of deliberate practice in expert performance: revisiting Ericsson, Krampe & Tesch-Römer (1993)", Royal Society Open Science 6: 190327, 2019. PMC
  11. K. A. Ericsson and R. Pool, Peak: Secrets from the New Science of Expertise, 2016; "Malcolm Gladwell got us wrong", Salon, 10 April 2016. salon.com
  12. N. K. Choudhry, R. H. Fletcher and S. B. Soumerai, "Systematic review: the relationship between clinical experience and quality of health care", Annals of Internal Medicine 142(4), 260–273, 2005. PubMed
  13. Secondary sources used: Macmillan Learning (1993 hours by group), The Strad (2019, replication hours), BPS Research Digest and Fox News (2016, the ~1% figure for elite athletes), Wharton Knowledge (interview with Ericsson).