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**Most people are below average!**Human performance is often

*not*distributed according to the famous 'bell curve' or 'Gaussian'. Instead, a small number of people vastly outperform the rest. A new study shows that in 186 out of 198 groups ranging from physics professors and Grammy nominees to cricketers and swimming champions, a small group of 'superstars' account for much of the success of the group as a whole. That means the majority are performing below the mathematical average - or to be precise, the 'arithmetic mean'.

This should not be depressing news, but it

*does*mean that blindly modelling people's behavior using a bell curve is a bad idea. So is expecting that 'average' means 'typical'.

If you want details, read the original paper - it's free online:

Ernest O'Boyle and Herman Aguinis, The best and the rest: revisiting the norm of normality of individual performance,

*Personnel Psychology*

**65**(2012), 79–119. http://onlinelibrary.wiley.com/doi/10.1111/j.1744-6570.2011.01239.x/full

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- +Jim Stuttard The last line of the abstract is also quite fun :
*We point out that programming teaching is useless for those who are bound to fail and pointless for those who are certain to succeed.*May 7, 2012 - A quick thought as to why the bell curve doesn't seem to apply to these industries. The statistical out liers at the bottom realized they should choose a different profession.

I'd love to be an artist, but I'm really, really bad at it, so I do something else to make a living. So I wouldn't be measured in their artistic samples.May 7, 2012 - +Kevin Burger I don't think you'd get two humps then?May 7, 2012
- Suppose players with skills distributed via normal (or any other, for that matter) distribution of skills repeatedly play in tournaments where the player with batter skill always wins the game. What will the distribution of prizes look like?May 7, 2012
- +Kevin Burger wrote: "I'd love to be an artist, but I'm really, really bad at it, so I do something else to make a living. So I wouldn't be measured in their artistic samples."

Indeed, in the radio show I laughed out loud when they said "what Aguinis is finding is that most people receive only one Grammy nomination..." Of course most people receive*no*Grammy nominations!May 7, 2012 - +Maksim Maydanskiy - if you repeatedly flip a coin and either win or lose a dollar based on the outcome, the probability distribution of your winnings or losses will be a Gaussian in the limit of many coin flips. But if you start with a dollar and either increase or decrease your money by 10% based on the outcome of each coin flip, the probability distribution will be lognormal. And the latter is closer to the actual the distribution of people's wealth.May 7, 2012