Sundays with the Enneagram

The “Three Centres” Myth – Part 3:

When “Science” Starts with the Answer

This week’s episode looks at what happens when someone sets out to “scientifically prove” the three centres instead of asking whether they make sense in the first place. In Personality and Wholeness in Therapy, Siegel builds a sophisticated-sounding framework of three “temperamental domains”: agency, bonding, and certainty, and then quietly fits them to the familiar Enneagram triads 8-9-1, 2-3-4, and 5-6-7.

The structure looks elegant on paper, but the direction of travel is wrong: it starts from the Enneagram narrative and works backwards toward neuroscience and clinical theory, rather than letting evidence lead wherever it wants to go.

The first move is the choice of exactly three domains. Neuroscience and psychology offer many different ways of carving up motivation and affect, and they do not converge on a tidy “there are exactly three fundamental human domains that just happen to sound like head, heart, and gut.”

Framing agency, bonding, and certainty as inborn “temperaments” may sound plausible in isolation, but without an independent reason for “three and only three,” it looks suspiciously like the number was chosen because the Enneagram already has three centres.

From there, each of these domains is further split into three positions (inside, outside, dyadic) to manufacture nine cells, which then line up perfectly with the nine Enneagram types, an outcome that tells you the model was being steered toward 9 from the start.

The biggest tell is the mapping itself: agency is assigned to 8-9-1, bonding to 2-3-4, certainty to 5-6-7, exactly as in the Narrative Tradition, as if that were an empirical discovery rather than a doctrinal starting point.

Wherever the fit is awkward, such as describing 9 as an “agency” type or 3 as inherently “bonding,” the theory leans on interpretive tricks like “disconnected from their domain” or “inverted expression,” which conveniently rescue the pattern from contradiction.

On top of this sit speculative gestures toward things like polyvagal theory and brain regions that are themselves contested or far more complex than “gut people have more vagal gut wiring, heart people more cardiac wiring.”

The result is not useless, because there are genuinely interesting ideas in the language of agency, bonding, and certainty, but it does not do what many in the community want it to do: it does not independently validate the three centres as real, brain-based structures.

It shows how easy it is to take a beloved Enneagram schema, decorate it with modern neuroscience vocabulary, and end up with something that feels more solid without actually being more testable or precise.

Next week: zooming in on one centre at a time and showing how, with a bit of narrative stretching, any type can be argued into any “triad,” which tells us something important about how flimsy the whole head/heart/gut grouping really is.