Isaac Asimov, the great science fiction writer and political philosopher, reasoned that "all things being equal, we root for our own sex, our own culture, and our own locality."
He was certainly referring to competitive events such as football and baseball games. The more someone acts, talks and communicates as we do, the more we tend to find them attractive.
In the classic story of "Evita", Juan Peron, the one-time dictator of Argentina, was able to quell a workers' riot. Dressed in formal military attire, he was taken to a riotous factory. While climbing up a ladder and addressing the unruly workers, he took his tie and jacket off, and loosened his shirt while rolling up his sleeves. He was then able to play the part of simply a "worker just like them" who happened to also be the dictator of Argentina.
You have probably heard it is important to wear a dark gray suit if you are selling to a professional. Yet, it is equally important to dress down to the level of your less well-heeled prospects.
Recently, a salesperson in Indiana relayed the story of his visit with a farmer. While he parked his car, he put on one of three jackets in his car reserved for his various prospects. Donning a simple plaid sports coat, he took his tie off, making sure he would not intimidate his prospect.