Some years ago, Nalini Ambady, an experimental psychologist at Harvard University, was curious about the nonverbal aspects of good teaching. She wanted to get at least a minute of film on each teacher to be rated, play the tapes without sound for outside observers, and then have those observers rate the effectiveness of the teachers by their expressions and physical cues.

She could only get 10 seconds worth of tape and thought she would have to abandon the project. But her adviser encouraged her to try anyway, and with 10 seconds of tape, the observers rated the teachers on a 15-item checklist of personality traits.

In fact, when Ambady cut the clips back to five seconds and showed them to other raters, the ratings were the same. They were even the same when she showed still other raters just two seconds of videotape. It seemed that anything beyond that first impression was superfluous.

Ambady's next step led to an even more remarkable conclusion. She compared those snap judgments about teacher effectiveness with evaluations made after a full semester of classes, by students of the same teachers. The correlation between the two, she found, was astoundingly high. A person watching a two-second silent video clip of a teacher he has never met will reach conclusions about how good that teacher is that are very similar to those of a student who sits in the teacher's class for an entire semester.

Tricia Prickett, an undergraduate at the University of Toledo, conducted a similar experiment. She collected videotapes of 20-minute job interviews in order to test the adage that "the handshake is everything." She took 15 seconds of videotape showing the applicant as he or she knocks on the door, comes in, shakes the hand of the interviewer, sits down, and is welcomed by the interviewer.

Like Ambady, she then got a series of strangers to rate the applicants on the basis of the handshake clip, using the same criteria that the interviewers had used for the original 20-minute interviews. Once more, against all expectations, the ratings were very similar to those of the interviewers. On nine out of the 11 traits on which the applicants were being judged, the 15-second observers predicted the outcome of the 20-minute interview.

The question is: Are first impressions good predictors because they are accurate, or are they simply more influential than subsequent (and contradictory) impressions? Do we see deeply quickly, or are we leaping to conclusions about people and ignoring evidence that contradicts our mental shorthand?

It turns out that our first impressions are not altogether accurate. Scientists call our tendency to leap to judgment the Fundamental Attribution Error. It's an error because how a person behaves in one situation is not an accurate predictor of her behavior in a different situation. We vastly underestimate the role of context in controlling human behavior and instead base our judgments on extremely limited information.

Nevertheless, as speakers, we can take advantage of this human frailty. When we step to the front of the room to deliver a presentation and all eyes are on us, we can take control using the tools at our disposal: physical, vocal, and verbal skills meant to capture the mind of the listener.

There are infinite ways to do this. Here are just a few:

  • Walk to the front of the room, your body filled with purpose.
  • Arrange your materials with concentrated and silent grace.
  • Take up your position, stand still with your weight on both feet, and gaze intently at the audience.
  • Let the silence become the blank canvas on which you will paint your masterpiece.
  • Pick a listener in the back of the room, look that individual in the eye, and deliver your opening line with confidence to that individual.

There are many types of opening lines, too.

A simple statement of your main theme or premise

For instance, Seth Godin gave a speech saying that marketing technical products was too important to leave to marketers. He began his speech by saying, "Marketing technical products is too important to leave to marketers." Pretty good summary headline, don't you think?

Asking for an audience response

"How many of you have ever wondered where your next meal is coming from?" And then wait for the hands to go up, or not.

A brief, gripping description of a problem faced by the audience

"Ladies and gentlemen, we have a problem. Our sales data is locked up in the laptops of our salespeople, and we can't get it out."

Painting a picture of the audience's world when the problem has gone away

"I wish you could have seen me. I had finished the presentation. People were standing and applauding, and my boss came up and said that was the best talk he'd ever seen. All my work had paid off. I was literally a changed person--loose, relaxed, and bubbling with all the attention."

Pointing out what you and your listeners have in common

"I am a professional speaker. I get paid for my performance. I believe you get paid for the same thing, except your performance lasts a year and mine only lasts an hour. Nevertheless, I stand on a stage, you sit at a desk, but we both get paid to perform."

A startling statement

"Every hour in Gaza, a child is dying from artillery fire and missiles."

Telling a story

"About a mile into the woods, my childhood friends and I discovered a hill that was covered with tall, dead trees..."

A personal anecdote

"I called a friend of mine and his answering machine said, 'Sorry, memory is full. Goodbye.' It made me think that many people are so preoccupied these days that they have no time, no space, no ability to listen."

Using a visual aid or prop

"This is a silicon wafer. It is made of one of the most common commodities in the world: sand!"

Using a famous quotation

"Acquisition of skills requires a regular environment, an adequate opportunity to practice, and rapid and unequivocal feedback about the correctness of thoughts and actions."

--Daniel Kahneman, Princeton psychology professor and Nobel laureate in economics

Starting with an intellectual puzzle

"We're always reading that there are literally millions of undiscovered insects in the Amazon rainforest. I'm completely stumped by the variety of creatures that show up on my front porch in suburban New Jersey. Who are they? What are their names? And why on earth are they knocking on my door?"

Using an analogy

"Public speaking is like splitting logs. You have to hit 'em where it counts, be sharp about it, and take a balanced stand on the issues."

If our listeners insist on attributing to us those qualities they glimpse in the first few seconds of our talks, despite subsequent evidence to the contrary, let us employ all means at our disposal to take advantage of their leap to judgment. Let us be masters of body language and wizards of the opening salvo. For speakers, it seems, all's well that begins well!