I’ve posted several times about what speakers should wear over the decade I’ve been blogging. It’s time for an update, because there’s some new research on what the science of dress dictates.

First of all, new research shows that formal business attire – suits for men, equivalent for women – increases your ability to think big ideas, abstract ideas, creative ideas.  All of those are good things for speakers, so suit up.  Consistent, of course, with several other important aspects of dress:  that it be consistent with your brand, that it be better than the audience, but not too much better, and that it be relevant to your talk.  So, for example, if you’re at an entrepreneurs’ conference in Silicon Valley, and everyone is dressed in t-shirts and jeans, you might wear a sports coat, but a suit would probably be overkill.  Bankers, on the other hand…..are going to expect a suit.  Maybe even a tie.

We negotiate better in a suit than in casual clothing.  So if you’re undertaking significant audience interaction, you may want to keep in mind that dressing up has the effect of empowering you in several ways.

But what if you’re speaking on creativity?  Then a suit could send the signal that you’re not really very creative.  In that case you’ll want to vary the more formal attire in some ways from the subtle to the not-so-subtle depending on your brand, again, and on the iconic statement you’re trying to make.  Think of Steve Jobs’ trademark black turtleneck and jeans.  He was signaling that he was different – not the standard corporate exec.  It worked very well for him.

One other study, fondly called the “red sneaker effect” by researchers, found that if you vary from the norm in a subtle way – wearing a red bowtie with your suit, or those red sneakers with your academic attire – then you will be perceived as more powerful and competent by the audience.  That probably happens because the audience makes the assumption that if you’re able to break the rules just a little you have confidence and authority.  Whereas if you break the rules too much you’re seen either as clueless or incompetent.  Or crazy.

The issue of dress is a very complicated one, because dress is one of the primary ways that we signal our attitudes, social status, relationship to the people around us, and a host of other issues.  Clothing is a sign – of status, profession, attitude, and so on.  So you want to think very carefully about your dress when you’re going to be standing in front of an audience, since all eyes will be upon you.

Finally, keep these three rules of thumb in mind, and you won’t go far wrong:  1) always dress a little better than the audience; 2) dress in a way that signals you’re at the top of your profession, category, or expertise; and 3) dress in a way that subtly shows you can break the rules with impunity.  The trick is not to take any of these rules of thumb too far.  You always want to dress in clothing that you’re comfortable in, that allows you to move easily, and that makes you feel like a million bucks.

My advice to clients is always to go to a top-end clothiers and splurge on a speaking outfit that makes you look fabulous.  You won’t regret sartorial splendor when all eyes are upon you.