Glamour days - "don't trust a guy who doesn't loosen his tie in the cockpit."
I had to think about that - wait a minute, *I* don't loosen my tie! But I used to...why did I change? And then it dawned on me, on newer technology jets (roughly 1980+, ie 757/767 or later), the air conditioning worked well enough that you didn't have to sweat yourself to death on the ground. So the tie is directly related to technology advancement and had nothing to do with the individual. Now it's rare to fly with a guy, on a modern jet, that loosens their tie because the air conditioning actually works on the ground.