Back in 1987, The Straight Dope's Cecil Adams wrote:
Dear Cecil:
Has there ever been, in the history of civilization, any functional purpose for wearing a tie, or is it merely an inane ritual held over from ancient times, unwittingly followed on a daily basis by hundreds of thousands of grown men as a blazing symbol of conformity to some unspoken norm, bestowing membership in some gigantic, vaguely defined, exclusive club? --Phil S., chairman, Loaded Questions Department, Washington, D.C.
Cecil replies:
I gather, Phil, that you do not like ties, probably because you are some kind of hippie beatnik who would rather live in the forest eating roots and berries than hold down a job like a man. But hey, no problem, I'm a liberal. The wearing of neck cloths dates back at least to the time of the Roman legions, when soldiers wore a neck band to catch the sweat or block the cold, depending on the season. In the 17th century, Louis XIV's Croatian regiment also wore neck cloths, whence we derive our word "cravat," from the French cravate, for "Croatian." Cravats, which were cloths wound around the neck and often tied at the ends, gradually evolved into the bow tie, and by the 19th century into the modern long tie.
Cravats were unquestionably an object of fashion, but at least they kept your neck warm, which is more than you can say for most modern neckwear. Regrettably, the trend over the years, in neckties as in all of life, has been to make once functional items increasingly useless. The State Department, for instance. But I digress. First the necktie migrated outside the collar (this was the high collar, I should note), the better to show it off. Then the collar was folded down, thus hiding the necktie and defeating the purpose of putting it outside the collar in the first place. At the same time the band part of the necktie, which wrapped around the neck, became thinner, until today we have those nerdy clip-on jobs with no band at all.
So far as I can determine, the only thing the tie does at present, apart from enforcing corporate discipline, is to hide your shirt buttons. Such a hassle. No doubt we'd all be better off if we could just get naked and frolic with the animals. I look to you, Phil, to show some leadership.