Every genogram has a center, and that center is not chosen at random. The index person determines whose story is told — and, by extension, whose story is not.
Definition
The index person — also called the index client or proband — is the individual whose family system is the focus of the assessment. In counseling, this is usually the person who came in for help. In research, it may be a selected reference person. The index person is marked with a double border around the standard symbol (square or circle).
This marking is more than cosmetic: it fixes the perspective. Every relationship descriptor — close, distant, conflictual — reflects the index person's perception, not some objective reality.
Changing Perspective
In family therapy with multiple clients, the question arises: who is the index person? The answer depends on the setting:
- Couples therapy: often two index persons, each double-marked — both perspectives are drawn in parallel.
- Family therapy: frequently the "identified patient" child, even though the system as a whole is the actual client.
- Supervision: the practitioner themselves, whose professional entanglement is being examined.
When perspective shifts within the same case, it is best to keep two separate versions of the genogram — not one version with two markings that blurs the center.
Centering
The index person should consistently be placed in the middle generation and centered horizontally. This is not just convention but a reading aid: anyone glancing at the genogram should be able to tell within seconds whose story it is.
A hidden or off-center index person is a common beginner's mistake — and usually a sign that the person drawing the genogram was themselves still unclear about whose story they were telling.