g-loading for pilots and astronauts

With the passing of Neil Armstrong, Charles Murray gives us this anecdote about Gemini 8:

Jerry began to reminisce about Gemini 8, Neil Armstrong’s previous space flight. Armstrong and his copilot, David Scott, had rendezvoused and docked with an Agena rocket as part of the rehearsal for techniques that would have to be used on the lunar mission. The combined vehicles had started to roll, so they undocked. But once it was on its own, the Gemini spacecraft started to roll even faster. Unbeknownst to the crew, one of the Gemini’s thrusters had locked on. The roll increased to one revolution per second.
I had known all this, but hadn’t thought much about it. And if you watch NASA’s version on You Tube, it is all made to sound as if the roll was a brief problem, never rising to the level of a crisis.
Actually, it was a moment that would have reduced me, and some extremely large proportion of the human race, to gibbering helplessness, no matter how well we were trained.
Imagine an amusement park ride that sits you in a pod, and that pod is twirled sideways at one revolution per second (you’ve never actually been on an amusement park ride remotely approaching that level of disorientation, because it would be prohibited). You have a panel in front of you with dozens of dials and small toggle switches, and you are supposed to toggle those switches in a prescribed sequence. While spinning one revolution per second. Pretty hard, trying to focus your eyes on those dials and coordinate your finger movement under those g forces so that you can even touch a switch that you’re aiming for. Now imagine that the sequence is not prescribed, but instead that there are many permutations, and you’re supposed to decide which permutation to do next based on what happened with the last one. Heavy cognitive demand there—long-term memory from training, short-term memory, induction, deduction. While spinning at one revolution per second. And now, to top it all off, if you don’t do it right, REALLY fast, you’re going to lose consciousness and die.
Jerry Bostick mused, “So there’s Neil, calmly toggling these little banana switches, moving through the alternatives, until he figures it out.” He shook his head in wonderment. “I’m not sure that any of our other pilots, and we had some great ones, could have analyzed the situation and solved it as quickly as he did.” I could forget about trying to make anything of Neil not being the first choice for the lunar landing.

As Tom Wolfe documented so memorably in The Right Stuff, many of the early astronauts were test pilots, men of exceptional skill and bravery. Now, astronauts are likely to be geezers with PhDs. Astronauts are likely to be very smart and hard-working, but we are probably no longer selecting for the skills Neil Armstrong exhibited.

Being smart is important to be a hell of a pilot, and if you run a statistical model on the data, as the Air Force has done, you will probably find general intelligence highly correlated with skill as a pilot. However, the Air Force decided to ignore the model, and continues to test for pilot-specific skills. Gemini 8 gives you a good idea why.