Information gaps in a genogram are themselves information. Practical strategies: pseudonyms, speculation markers, and the later-addition principle.

The most common obstacle in the genogram

Anyone who teaches genogram work hears it early on: "My client doesn't know anything about their grandparents. What do I do now?" The answer: That, too, is a genogram. Only the question of how to handle it professionally is new.

Gaps have reasons. Some are biographical (grandparents who died young, war losses, emigration), some are systemic (silenced topics, family secrets, conflicts with intergenerational rupture), some are generational (younger clients often know less about their grandparents because family communication has changed). The strategy depends on the reason.

Strategy 1: Structured pseudonyms

When the paternal grandfather is unknown by name but did exist, he gets a structural pseudonym: "GF-P" for paternal grandfather, "GM-M" for maternal grandmother. This may sound sober but it is precise — and it takes the taboo out of the gap. Clients can see that the person has been recorded systemically, even if the name is missing.

Important: pseudonyms must not become avoidance. If after three sessions the grandparents are still only "GM-P", that is a cue either to ask within the family for once — or actively to decide not to ask.

Strategy 2: The speculation marker

Some clients suspect things about their grandparents but know nothing for sure. These suspicions belong in the genogram — but marked as such. I use small curly braces: "{probable alcohol problem}", "{probably war}", "{probable estrangement}".

This marking does two things. First, the suspected content becomes visible without being treated as fact. Second, it can be verified later — through family research, conversations, sometimes through archival work.

Speculation is not diagnosis. But it is clinically effective — families often have very accurate intuitions about what happened in previous generations. These intuitions deserve a place in the picture.

Strategy 3: The later-addition principle

A genogram is never finished. Conveying this to clients frees them from having to know everything in the session. Standard line: "What you don't know today, you can add — in six months, in five years, or never. The genogram remains open."

Concretely, that means: gaps stay visible, but the picture is still treated as workable. Later sessions can integrate new information. In some cases the client brings an old family photo months later — and suddenly there are names.

Strategy 4: Respecting active non-research

Some clients do not want to know anything about their grandparents. That, too, is a valid position. A counsellor who pushes the client into research may be disregarding an important self-protective decision.

Question: "Would you want to know more if you could?" — the answer reveals whether the not-knowing is deficit or protection. Both are legitimate.

Practice vignette

A 28-year-old client knows nothing about her father — her mother never showed him to her. She has a name, no image, no story. In the genogram there is a square with a question mark. She says: "I don't actually want to know anything either." We leave it like that.

Six months later: she comes in with a letter. She had googled the name, found a distant relative, exchanged messages. The square now gets a year of birth and a profession. Nothing more. But the picture has become different — and so has she.

Practice vignette 2

Family with grandparents who died in the war — three of the four in bombing raids. The client (born 1958) knows the names of her own parents and one grandfather per line, nothing more. We mark the missing ones with "{war †}" and accept that. The gap is the family's history.

What does not work

Overpainting the gaps. When the client doesn't know, "tell me what you imagine" doesn't help. That produces confabulation, not a genogram. Better to be honest: "You don't know that. We mark it as such."

And: framing gaps as a deficit of the client. "You don't know much about your family" — one sometimes hears this from counsellors, and I hear it in supervisions too. Such statements are intrusive. Gaps are not blame; they are information.

Further reading