Matt Brad doesn’t make a reference in his book. But Heart, Gut and Head could refer to the Triads or the Centres in the Enneagram theory.
The Enneagram describes different groups of behaviours and characteristics and could be used for identifying the character of the MC and/or Protagonist.
In Enneagram there are 9 types.
If you don’t know the type of your Protagonist or don’t have a glue yet about the Antagonist and other players the Enneagram might help:
Example: When your Protagonist is a Type 7 (Problem of PURSUIT … Options, Adventure, Fun)
- Type 1 as Antagonist (1 focus on Perfection and is the Stress-Point of 7)
- Type 4 as Influence (4 focus on Uniqueness, arrive at the same place by variant processes)
- Type 3 as Sidekick (3 focus on Success, both types have similar modes of expression)
- Type 6 as Guardian (6 focus on Security, parent-child-feeling)
- Type 9 as Reason (9 focus on Harmony, prefer similar climates without having much in common)
- Type 5 as Skeptic (5 focus on Insight, a puzzle and totally foreign in nearly every facet)
A mapping of Dramatica Elements with Enneagram types you can find here:
On the web there is a lot of material. Two books I can recommend working with Dramatica (no commercial interests from my side):
- Thomas Condon, The Enneagram Movie Guide
- Jens Becker, Script-Tool: Enneagram 2.0