When U.S. air force discovered the flaw of averages (2016)
Note that this is not some sort of unexpected effect due to humans not behaving mathematically ideally; this is what happens when your intuitions about 1, 2 and 3 dimensions are applied to higher dimensional spaces. Consider the goal of being in the middle 50% of a random value on one dimension; you have a 50% chance. But if you have two dimensions, and you want to be in the middle 50% for both of them, it's a 25% chance. And if you have 3, it's a ~12% chance. This already is counterintuitive, but when you ramp it up to 10 dimensions, it's a ~0.01% chance. That means that if you have a thousand people, only one of them (on average) will be in the middle 50% of all of them. Even the praised end state of the air force, with 9 dimensions and a required support of 90% of individuals of each dimension, implies that only 38% of individuals will be supported overall. (Granted, human dimensions aren't wholly uncorrelated.)