It is an excerpt from a new book The End of Average by Todd Rose.
Out of 4,063 pilots, not a single airman fit within the average range on all 10 dimensions. One pilot might have a longer-than-average arm length, but a shorter-than-average leg length. Another pilot might have a big chest but small hips. Even more astonishing, Daniels discovered that if you picked out just three of the ten dimensions of size â€” say, neck circumference, thigh circumference and wrist circumference â€” less than 3.5 per cent of pilots would be average sized on all three dimensions. Danielsâ€™s findings were clear and incontrovertible. There was no such thing as an average pilot. If youâ€™ve designed a cockpit to fit the average pilot, youâ€™ve actually designed it to fit no one.
This is similar to material that I have read in some copy-writing books recently. Target a specific person and not to a general audience for a product.
Here is the book mentioned.