Dr. Dario Nardi studying the brain of different personalities came to this conclusion while watching EEG scans of various people.
How engaged a person is with what you are telling them boils down to their competence in a subject and likely to be able to understand the background of what you are speaking about and the motivation that they have to learn the subject.
Dr. Dario Nardi literally watched brain signals light up on people to learn this and looked at when their brains lost interest. When people lost motivation, their brain signals dropped off entirely. When they weren’t competent they never even started.
Here’s a thought that can be extracted from this: “Start with Why.” (Thanks Simon Sinek!)
If the audience isn’t competent in the subject you are speaking about, then start with motivation, why should they listen to you. From there, you need to set the competence base level, give them the background. If they are already competent, then they only need the motivation, so the why wins again.
I don’t have the chart, but I can’t stress enough, when people lost motivation, their mind shut off completely! Reminding them of the motivation throughout a long presentation may be necessary!
Speaking simply to keep the audience at the right competence level is also necessary.
While this may not be an earth shattering discovery, and people already know this stuff (see my note on Simon Sinek), it’s great to find qualitative studies like Sinek’s matching more quantitative studies like Dr. Nardi’s. Use this work, it’s powerful stuff.