[Pelham]

Well hat makers at the time believed it because American men stopped wearing hats in the early ‘60s. But here’s another interesting take:

http://www.npr.org/sections/krulwich/2012/05/04/152011840/who-killed-mens-hats-think-of-a-three-letter-word-beginning-with-i

[jjotto]

I definitely agree with that! As cars got “longer, lower, wider”, hats got more difficult to deal with. Men switched to baseball or driving caps unless it was a more formal occasion. I saw this with my grandfather.