Clinical standards
Genogram rules: the 15 conventions of standard notation
Quick answer
Why do genogram rules matter?
Without standardized rules, a genogram created by one clinician cannot be reliably interpreted by another. The entire value of the genogram as a clinical tool depends on shared conventions: when you see a square, you know it represents a male; when you see a zigzag line, you know it indicates hostility. This shared language is what makes genograms useful across treatment teams, supervisory sessions, case consultations, and published research.
The standard notation system used today was developed and refined by Monica McGoldrick, Randy Gerson, and Sueli Petry over several decades of clinical work and academic collaboration. Their definitive reference, Genograms: Assessment and Treatment (4th edition, 2020), published by W.W. Norton, is the most widely adopted standard in family therapy training programs worldwide. These rules ensure that genograms function as a shared clinical language rather than personal shorthand.
The McGoldrick-Gerson standard
The 15 essential genogram rules
- 1
Males Are Squares, Females Are Circles, Non-binary an Arch, Unknown a Diamond
The most fundamental rule: males are represented by squares, females by circles, non-binary by an arch (rounded top, flat bottom), and unknown or other gender identities by diamonds. This convention is standard in clinical practice.
Male
Female
Non-binary - 2
The Index Person (IP) Has a Double Border
The identified patient or person of focus is indicated by drawing a double border around their symbol. This immediately tells any reader who the genogram centers on.
- 3
Deceased Individuals Get an X Through Their Symbol
When a family member has died, draw an X through their square, circle, or diamond. The year of death should be noted beside the symbol.
Deceased - 4
Generations Are Arranged Horizontally on the Same Row
Each generation occupies its own horizontal level. Grandparents at the top, parents in the middle, children at the bottom. This vertical hierarchy is essential for readability.
- 5
Oldest Siblings on the Left, Youngest on the Right
Within each sibling group, birth order reads left to right, with the firstborn on the far left and the youngest on the far right. This convention ensures consistency across all genograms.
- 6
Marriages and Partnerships Connect with Horizontal Lines
A horizontal line connects two partners. The male is traditionally placed on the left and the female on the right, though this convention is flexible in modern practice.
- 7
Children Descend Vertically from the Couple Line
A vertical line drops from the horizontal couple line, then branches to connect to each child. Children hang from this line in birth order (left to right).
- 8
Structural Relationships Use Specific Line Patterns
Marriage is a solid horizontal line, separation adds one diagonal slash, divorce adds two diagonal slashes, and cohabitation uses a dashed line. These structural lines show legal/formal relationship status.
Cohabitation
Engagement - 9
Emotional Relationships Use Distinct Line Patterns
Emotional relationships are shown between any two people: close (double line), enmeshed or fused (triple line), distant (dotted line), conflictual (zigzag line), cutoff (line with break). These are distinct from structural lines, and they are defined by pattern, not colour.
Close
Fused
Distant
Conflict
Cutoff - 10
Twins Connect to the Same Point on the Descent Line
Identical twins connect to the same point with a horizontal bar between them. Fraternal twins connect to the same point without the bar. This distinguishes twin type at a glance.
- 11
Miscarriages and Stillbirths Have Specific Smaller Symbols
A miscarriage is shown as a triangle with an X through it, an abortion as the same triangle with a bar across its base, and a stillbirth as the person’s own gender shape drawn at half size with an X. Pregnancy loss symbols are always smaller than standard symbols.
Miscarriage - 12
Adoption Uses Dashed Lines to Adoptive Parents
Adopted children connect to their adoptive parents with dashed lines and to their biological parents (if known) with solid lines. This visually distinguishes biological from legal relationships.
- 13
Include at Minimum Three Generations
A clinically useful genogram must include at least three generations: the index person, their parents, and their grandparents. This minimum allows pattern recognition across generational lines.
- 14
Include Dates: Birth, Death, Marriage, and Significant Events
Every individual should have birth year noted. Deaths, marriages, divorces, and significant life events should include dates. This temporal data is essential for identifying age-related patterns and life cycle transitions.
- 15
The Genogram Should Be Readable Left-to-Right, Top-to-Bottom
The overall flow follows Western reading order: older generations at the top, younger at the bottom, older siblings on the left. This ensures any clinician can quickly orient themselves to the family structure.
Genogram rules at a glance
| Topic | Rule | Rule no. |
|---|---|---|
| Who is who | Square = male, circle = female, arch = non-binary, diamond = unknown | 1 |
| Focus person | Double border around the index person | 2 |
| Death | X through the symbol, year of death beside it | 3 |
| Generations | One horizontal row per generation, oldest at the top | 4, 13 |
| Birth order | Oldest sibling on the left, youngest on the right | 5 |
| Couples | Horizontal line; one slash = separation, two = divorce, dashed = cohabitation | 6, 8 |
| Children | Vertical line down from the couple line, in birth order | 7 |
| Emotional lines | Pattern, not colour: double = close, triple = fused, zigzag = conflict | 9 |
| Twins, loss, adoption | Shared point for twins; small triangle for miscarriage; dashed line for adoption | 10-12 |
| Dates | Birth year for everyone; dates for deaths, marriages, divorces | 14 |
What are the most common genogram mistakes?
Mixing Up Structural and Emotional Relationships
Not Aligning Generations Horizontally
Forgetting the Index Person Marker
Inconsistent Symbol Sizes
Missing Dates and Ages
Overcrowding Without Spacing
How GenogramAI applies these rules
- 1
AI auto-alignment and generational layout
GenogramAI automatically arranges family members into correct generational rows. Siblings are ordered by birth date, generations are horizontally aligned, and spacing is optimized so your genogram follows Rules 4, 5, and 15 without manual adjustment. - 2
Standard symbols and notation
Every symbol GenogramAI places is consistent with McGoldrick-Gerson conventions. Squares for males, circles for females, arches (rounded top, flat bottom) for non-binary, diamonds for unknown or other gender, double borders for the IP, X marks for deceased, and correctly sized symbols for miscarriages and stillbirths. Rules 1-3 and 10-12 are applied by default. - 3
Auto-Arrange and a final review
The Auto-Arrange window offers As is, Tidy and Compact layouts drawn from your own genogram, so generations stay aligned after edits. On paid plans, the PDF report can add AI Insights, a tentative clinical reading of the family. There is no automatic rule checker, so give the chart a last pass against the rules above before you export.
Genogram rules: questions
Who created the standard genogram rules?
The standardized genogram notation system was developed primarily by Monica McGoldrick, Randy Gerson, and Sueli Petry. Their book "Genograms: Assessment and Treatment" (now in its 4th edition, 2020) is the definitive reference for genogram conventions. The system has been refined over decades based on clinical practice and input from the family therapy community.
Are genogram rules the same worldwide?
The McGoldrick-Gerson notation system is the most widely accepted standard internationally, used in clinical training programs, textbooks, and professional practice across countries. While minor variations exist in some regional traditions, the core rules for symbols (squares for males, circles for females), relationship lines, and generational layout are consistent across the field.
Can I modify genogram rules for my specific clinical needs?
While the core symbol and structural rules should remain standard to ensure readability, clinicians often add specialized annotations for their area of practice (e.g., trauma markers, addiction symbols, cultural genogram elements). The key principle is: keep the foundational notation standard so any clinician can read it, and clearly label any custom additions.
How many generations should a genogram include?
The standard rule is a minimum of three generations: the index person's generation, their parents' generation, and their grandparents' generation. However, many clinical situations benefit from four or more generations, especially when tracking intergenerational patterns like addiction, mental illness, or trauma transmission.
What is the most commonly broken genogram rule?
The most common mistakes are confusing structural relationship lines (marriage, divorce, separation) with emotional relationship lines (close, conflictual, enmeshed), and failing to align generations horizontally. These errors make genograms difficult for other clinicians to interpret and can lead to clinical misunderstandings.