Inside Business January 2012. See the original article here .

I was recently interviewed by a sales expert, and at the beginning of the conversation he was adamant that when he made cold calls he always dressed down. That is to say, he often wore a polo shirt with Bermuda shorts, because he lives in a beach city. His theory is that if you wear a tie and carry a clipboard or briefcase, you'll look like a salesman and you won't stand a chance of getting your foot in the door.

As we got into the interview, he confessed that in a non-sales environment, he always got deferential treatment when he wore a suit and tie. It's likely that had he worn a tie and dropped the briefcase, he would have been given deferential treatment at his cold calls.

As for being treated special, it isn't necessary to wear a formal-looking suit to look important and get extraordinary treatment. When a man wears dark trousers, a friendly blue dress shirt and a tie, he looks more credible than a man in Bermuda shorts.

When you show up in Bermuda shorts, you'd better be very attractive, classy and charming, and the resort-city sales expert just happened to have all those qualities. Social psychologists confirm that we assume that people who look good are good at what they do. Nevertheless, two men with the same level of attractiveness and charm will discover that professional attire bestows far more credibility than casual attire can ever do.

As all salespeople know, we like to buy but we don't like to be sold. That's why salespeople take the time to build a relationship. Sometimes that takes awhile, but that time can be shortened by a positive first impression.

It's a mistaken belief you need to mirror your customer's attire. It's acknowledged that we do buy from people we like, but part of liking a person is the element of trust. If your image and demeanor are polished and impeccable, chances are your prospective client will take notice and assume you're trustworthy. It isn't necessary to dress down to garner trust from a casually attired person; however, you don't want to be dressed like a bank president. Professional attire has many levels, but it doesn't include Bermuda shorts, khakis or polos.

Josh, an expert in social media, was a member of a networking group that met once a week, and he didn't deem it necessary to wear a shirt and tie to these breakfast meetings. His business was doing OK, but he had hoped for more referrals from the group. Then he showed up in a suit and tie.

"Everyone treated me as if I were a VIP guest," he said, "and suddenly, they wanted to introduce me to important executives in town. I soon realized it was because I looked like a CEO and not a guy working out of his spare bedroom."

Within a month, Josh had more referrals that he'd had in a year.

When you change your image, you will change the attitude of others toward you. Attitude isn't the only thing that changes. When you change your image, the outcome also changes.