As a business executive, I think most of us have been requested or invited to speak publicly, no matter it's for a client brief, training, presentation, seminar or conference.
Assuming if you're invited to deliver a 45-minute public speech, if you were a great speaker, in order to maximize the effectiveness of your speech, should you speak longer or shorter than the required time? I guess most of you will say 'shorter'. Right? How about if you were a lousy speaker--speak even 'shorter'? Then no matter you were a great speaker or a lousy speaker, you should always speak shorter than the required time? No, you shouldn't. If you were a lousy speaker, the better move is: speak as longest as you could.
Let me explain why. Noble prize-winning psychologist Daniel Kahneman pointed out people could remember only two things during an experience process: how we feel at the peak (no matter whether the ultimate experience was good or bad) and at the end. We remember only the peak and the end. (See Peak-End Rule [1]) And, whether we feel satisfy or not, is not solely the experience, but is also affected by expectation. Satisfaction = Experience - Expectation. That's why although we deliver better and better experiences to our customers, it doesn't mean they're more satisfied as their expectations are being raised as well.
Now, I will illustrate my idea by mapping the emotional feelings of audience from the beginning till the end of a speech in natural time sequence. I call it Emotion Curve [2].
Emotion Curves--Lousy Vs. Great Speakers
The Effective Memories
In the case if I were a great speaker, the experience of audience is rising (Emotion Curve in Blue: Great Speaker) as my speech starts and goes on. However, no matter how great you're as a speaker, the emotional feeling will start to decline, that means they won't feel as pleasurable as before at some point--as the expectation of audience is being raised, they will expect a better joke or better content, even though you could maintain the same high level of speech quality. Thus the best move is to finish shorter than expected, for example, in 30-minute, then the effectiveness of the speech is maximized (as the peak and end generate the strongest positive emotional feeling). The longer the speech, the weaker the impact it will be.
In the case if I were a lousy speaker, the experience of audience is decreasing (Emotion Curve in Red: Lousy Speaker) since my speech starts. However, your audience are being trapped in the room (assuming they can't leave), they probably think "Oh that's my destiny!", and their expectations are being lowered, so the same level of negative experience would be felt less painful. The best move is to speak as longest as you could, say 60-minute or more, in order to minimize the negative peak and end. If you end up in only 30-minute, what you will deposit in the audience's memories: "Oh, this's the most lousiest speech than I've ever heard!"--don't try it.
We Need More Pain [3], but not in that way!