How to read a genogram — symbols, lines and patterns explained

Start with the legend

Before you read a single shape, find the legend. Most well-drawn genograms include a key in a corner of the page that defines the symbols the clinician chose to use. This step matters more than it sounds, because genogram notation is not fully standardized. The system developed by Monica McGoldrick and Randy Gerson differs in small but meaningful ways from the Bowen Family Systems notation and from the standards published by the North American Association of Social Workers (NASW). A bold horizontal line between two individuals means “close bond” in one system and “married” in another.

If there is no legend, your first task is to identify which convention the clinician used — often discernible from their training background or the clinical setting. Hospital social workers in North America frequently use the NASW standard. Family therapists trained in systemic approaches tend to follow McGoldrick. When in doubt, ask. A genogram read under the wrong key can produce serious clinical misinterpretations.

For a detailed breakdown of the most common symbol sets, see the genogram key reference and the full guide to genogram symbols. Both pages display symbols side by side with their meanings and note where conventions diverge.

Reading the basic shapes

The shapes on a genogram encode sex, vital status, and clinical significance. Once you know the vocabulary, identifying individuals and their basic characteristics takes seconds.

A square represents a male individual. A circle represents a female individual. A triangle represents a pregnancy, miscarriage, or unborn child, depending on context and any notation inside it. A diamond represents a person of unknown or unspecified sex — common for distant relatives about whom little is known. When any shape has an X drawn through it, that individual is deceased. The year of death and the cause of death (if known) are typically noted beneath the crossed-out shape.

Numbers inside a shape indicate the person’s current age if they are living. For deceased individuals, the age at death appears inside the shape and the year of death appears below it. Some clinicians write both birth year and death year in a format such as “1943–2014” beneath a crossed square.

The single most important shape to locate when you first pick up a genogram is the double-bordered shape — a square or circle drawn with two concentric lines instead of one. This marks the index person (IP), also called the identified patient or the presenting client. Everything else on the diagram is oriented around this individual. Find the double border first. It anchors your reading.

For a full illustrated reference to shapes including less common variants (twins, foster children, stillbirths), see the genogram symbols page.

Reading structural relationship lines

Structural lines show the legal and biological architecture of the family — who is partnered with whom, who gave birth to or adopted whom, and how siblings relate. These lines say nothing about the emotional quality of a relationship; they describe only its formal structure. Understanding this distinction early prevents most beginner errors.

A single horizontal line connecting two shapes indicates a relationship or partnership of some kind. The more specific line types then refine what kind:

• Double horizontal line — a legal marriage. Two parallel horizontal lines join the couple’s shapes.
• Dashed horizontal line — an unmarried partnership or cohabiting couple. The relationship is committed but not legally formalized.
• Single horizontal line with one diagonal slash — a separation. The couple is no longer living together but has not legally divorced.
• Double horizontal line with two diagonal slashes — a divorce. The marriage has been legally dissolved.

Sequential relationships (remarriages or serial partnerships) appear on the same individual. By convention, the earliest relationship is drawn to the left and later relationships extend to the right. When reading a person with multiple partnerships, work from left to right chronologically.

Children descend from the couple line. A vertical line drops down from the center of the couple’s horizontal relationship line, then branches into a horizontal “sibship line.” From that sibship line, individual vertical lines drop down to each child’s shape. Siblings are ordered left to right from oldest to youngest. If a child was adopted, the vertical line from the sibship line to that child is drawn as a dashed line rather than a solid one. For children born to only one partner from a prior relationship, the vertical line connects to that parent’s shape directly rather than to the couple line.

These structural lines form the scaffold of the genogram. Once you have traced the family scaffold across three generations, you have the map. The emotional content comes next, in a separate layer of lines.

Reading emotional relationship lines

Emotional relationship lines are where most beginners get confused — and where the clinical richness of the genogram lives. Unlike structural lines, which run along the family scaffold (horizontal between couples, vertical to children), emotional lines are drawn between any two individuals in the family to describe the quality of their bond. They can run diagonally, across generations, and across branches of the family.

The major emotional line types in the McGoldrick/NASW system are as follows:

• Three parallel lines (or a bold single line) — a close or strong bond. The relationship is warm, supportive, and reliable.
• Three parallel lines with additional cross-marks — an enmeshed or fused relationship. Boundaries are poorly defined; the individuals are overinvolved in each other’s lives. Differentiation is low.
• Dashed line — a distant or weak relationship. The bond is present but thin — little contact, emotional withdrawal, or chronic disengagement.
• Zigzag line — a conflictual relationship. Regular conflict, tension, or hostility characterizes interactions.
• Dashed zigzag line — a relationship that is simultaneously distant and conflictual. Contact is minimal, but when it occurs it is marked by friction.
• Three parallel lines with a cut (break in the line) — a cutoff. The relationship has been severed, either by one party’s deliberate estrangement or by mutual cessation of contact.
• Arrow line — a focused or preoccupied relationship. One individual is directing intense attention, anxiety, or focus toward another. The arrowhead indicates the direction of that focus.

How do you distinguish emotional lines from structural ones? Three practical cues: First, emotional lines typically connect the shapes themselves (touching the border of a square or circle) rather than running along the family scaffold. Second, in color-printed or digital genograms, emotional lines are often drawn in a second color — red or blue — to separate them visually from the black structural scaffold. Third, emotional lines can run in any direction, while structural lines follow predictable horizontal and vertical geometry.

When a genogram is hand-drawn or poorly formatted, these visual distinctions can collapse. In that case, ask whether any diagonal line connects two individuals who are not in a couple relationship — if so, it is almost certainly an emotional line. For a complete visual reference to all emotional line types, see the genogram relationship lines page.

Reading a genogram step by step — a worked example

The best way to solidify notation knowledge is to read an actual genogram systematically. Consider the Martinez family, a composite three-generation diagram constructed for teaching purposes.

Generation I (grandparents). At the top left is a crossed square labeled “José” with the notation “71, MI” — indicating that José was male, died at age 71 from a myocardial infarction. To his right, connected by a double horizontal line (marriage), is a circle labeled “Elena, 74, HTN” — Elena is living, age 74, with hypertension. The double line indicates 48 years of marriage; a small “48 yrs” note appears on the couple line. José is deceased; Elena is the surviving spouse.

Generation II (parents). A sibship line descends from the José–Elena couple line and branches to two individuals. On the left is a square labeled “Roberto, 48” — the older sibling. Roberto is connected by a double horizontal line to a circle, “Ana, 45” — they are married. On the right of the sibship line is a circle labeled “Carmen, 44.” Carmen shows two sequential relationships. To her left, a double line with two slashes connects her to a square labeled “Miguel, 47” — a dissolved marriage. To her right, a double horizontal line connects her to a square labeled “David, 50” — her current husband.

Generation III (index generation). From the Roberto–Ana couple line, a sibship line descends to two children. On the left is a double-bordered square labeled “Marco, 22” with the notation “Anxiety disorder” below it. The double border identifies Marco as the index person — he is the presenting client. To his right on the sibship line is a circle labeled “Sofia, 19.” On Carmen’s side, her first marriage to Miguel produced two children: a square labeled “Luis, 17” and a circle labeled “Nina, 14,” both connected by a sibship line to Carmen’s first relationship line.

Emotional lines. Several emotional lines are drawn across this family. A three-parallel-line-with-marks runs between Elena and Roberto, indicating an enmeshed bond between grandmother and son. A dashed line connects Elena and Carmen, indicating a distant relationship. A zigzag runs between Marco and Roberto, indicating conflict in the father–son relationship. Three parallel lines (no marks) connect Marco and Ana, indicating a close bond with his mother. A cutoff line — three parallel lines with a break — connects Carmen and Miguel, indicating that the post-divorce relationship has been severed entirely.

How a clinician reads this in sequence. Step one: find the index person. The double-bordered square immediately identifies Marco. He is 22, male, presenting with an anxiety disorder. Step two: read Marco’s generation. Marco is the older of two children; his sister Sofia is three years younger. Positionally, Marco is the eldest child — a role associated in family systems theory with higher anxiety loads and parentification risk.

Step three: move up to the parental generation. Roberto and Ana are married, which suggests a stable household structure. But Carmen’s history introduces complexity on the extended family side: divorce from Miguel, cutoff post-divorce, and remarriage to David. Two of Marco’s cousins (Luis and Nina) are children of a fractured first marriage with no ongoing contact between their parents.

Step four: move up to the grandparents. José died at 71 of a myocardial infarction. Elena at 74 has hypertension. This is a two-generation flag for cardiovascular risk on the paternal side — directly relevant to Marco’s male relatives and worth noting in any medical history. José’s early death also means Roberto grew up without a father for some portion of his adult life, and that Elena became a widowed matriarch.

Step five: read the emotional lines as a system. Elena and Roberto are enmeshed. Elena and Carmen are distant. This split pattern — one adult child fused with the parent, the other cut off — is a classic indicator of unresolved triangulation from the grandparental generation. Roberto carries Elena’s emotional weight. Marco, in turn, is in conflict with Roberto (zigzag) but close to Ana (three parallel lines). The conflict between Marco and his father may partly reflect the pressure Roberto carries from his enmeshed relationship with Elena — stress that flows downward through generations.

Step six: name the patterns. Three stand out immediately. First, cardiovascular risk runs paternal-lineage: José (MI, deceased), Elena (HTN). Second, emotional distance characterizes Elena’s relationship with Carmen and Carmen’s post-divorce cutoff with Miguel — a pattern of relational severance on the maternal branch. Third, the enmeshment between Elena and Roberto, combined with Roberto–Marco conflict, suggests multigenerational transmission of anxiety and boundary difficulties. Marco’s presenting anxiety disorder does not exist in isolation — it appears embedded in a family system with identifiable relational patterns stretching back at least two generations.

Common reading mistakes

Even experienced readers make predictable errors when approaching an unfamiliar genogram. Knowing them in advance reduces the chance of misreading.

Confusing structural and emotional lines is the most frequent error. A zigzag drawn near a couple line does not mean their marriage is conflictual — it means the zigzag connects two specific individuals, which may or may not be that couple. Always trace where the line terminates before interpreting it.

Missing the index person happens when readers scan the page visually without first searching for the double border. Start with IP identification every time, without exception.

Ignoring deceased members is a clinically costly mistake. Crossed shapes carry critical information — cause of death, age at death, and timing relative to family events. A grandfather who died of lung cancer at 58 creates hereditary risk for every descendant. A grandmother who died when her son was 14 creates a developmental loss event that may shape that son’s attachment patterns decades later.

Reading left to right instead of generation by generation fragments the family structure. Always read horizontally within a generation first, then move vertically between generations.

Treating the genogram as a static truth rather than a snapshot is a subtler error. Genograms capture a family at a specific moment. Relationships that appear conflictual may have since resolved; cutoffs may have healed. Always note when the genogram was drawn and treat it as a clinical hypothesis, not a permanent record.

What different disciplines look for

Different clinical disciplines use genograms to answer different questions. The notation is the same; the interpretive lens is not.

Social workers

Social workers reading a genogram prioritize patterns of abuse, neglect, and substance use across generations. A genogram may reveal that substance use appears in multiple members of the same generational cohort, or that neglect patterns repeat across parent and grandparent generations in a way that informs a current child welfare assessment. Social workers also use genograms to evaluate caregiver availability — who in the extended family network is present, connected, and potentially able to provide support — and to identify kinship placement candidates when a child cannot remain with their primary caregivers. The breadth of the family map, not just the nuclear household, is the unit of analysis. See genograms in social work for a discipline-specific overview.

Therapists and counselors

Family therapists and counselors focus on systemic patterns: triangles (two individuals in close alliance with a third individual caught in the middle), enmeshment, emotional cutoffs, and the identified patient role. From a Bowen systems perspective, the genogram reveals how anxiety moves through the family system — who is the “symptom bearer,” how differentiation varies across the family, and where multigenerational transmission of depression, anxiety, or trauma is visible. The emotional lines are the primary clinical data for therapeutic work. See genograms in therapy and genogram psychology for depth on these applications.

Nurses

Nurses use the genogram primarily as a medical history tool. The vertical transmission of hereditary disease — cardiovascular disease, type 2 diabetes, breast and ovarian cancer, hereditary colorectal cancer syndromes — is visible immediately when causes of death and diagnoses are recorded on the shapes. A nurse reading a three-generation genogram can identify at-risk family members who have not yet developed symptoms but whose family history warrants early screening. The genogram also surfaces family communication dynamics around health decisions — who in the family is the medical decision-maker, who avoids healthcare, and whether patterns of non-disclosure about diagnoses are present. See medical genogram and genograms in nursing for clinical nursing applications.

From reading to interpretation — spotting patterns

Reading a genogram is decoding the notation. Interpreting it is making clinical sense of the patterns. The two are related but distinct skills.

Once you have read the shapes, structural lines, and emotional lines accurately, shift your attention to patterns across the diagram. Look for symptom concentration — do medical diagnoses or psychiatric presentations cluster in one generation or one branch of the family? Look for triangles — a characteristic three-person configuration in which two closely connected individuals manage their tension by pulling in a third. Look for multigenerational transmission: does a specific relational pattern (enmeshment, cutoff, substance use, early paternal death) repeat across generations at similar life-stage intervals?

These observations transform a diagram into a clinical hypothesis. They guide questions in the clinical interview and suggest where the historical work of therapy or the preventive work of medicine may need to go. The genogram interpretation guide covers these interpretive frameworks in detail, including Bowen systems concepts, attachment patterns, and family resilience factors.

Frequently asked questions

What does a square mean in a genogram?

A square represents a male individual. If the square has an X drawn through it, the person is deceased. A square with a double border — two concentric square lines — marks the index person (identified patient), the primary subject around whom the genogram is organized.

What do the horizontal lines between people mean?

Horizontal lines between two individuals indicate the type of relationship or partnership between them. A single horizontal line is a generic relationship. A double horizontal line is a legal marriage. A dashed horizontal line is an unmarried partnership. A single line with one slash indicates separation; a double line with two slashes indicates divorce. Emotional relationship lines — which look different from structural lines — are separate and convey the quality of the bond, not its legal status.

How do you read emotional relationship lines?

Emotional relationship lines connect the shapes of two individuals directly and can run in any direction. They are distinct from structural lines, which follow the family scaffold. Common types include three parallel lines (close bond), a zigzag (conflict), a dashed line (distance), a dashed zigzag (distant and conflictual), three lines with a break (cutoff), and three lines with cross-marks (enmeshment). The legend confirms which system the clinician used. For a visual reference, see the relationship lines page.

What does a double border mean in a genogram?

A double border — a shape drawn with two concentric outlines — identifies the index person (IP) or identified patient. This is the individual who is the primary subject of the clinical assessment: the presenting client, the patient, or the person whose situation prompted the genogram to be drawn. Locate this shape first when reading any genogram.

How many generations should a genogram show?

The standard clinical genogram covers three generations: the index person’s generation, the parental generation, and the grandparental generation. Three generations are generally sufficient to reveal multigenerational transmission patterns. In specific contexts — hereditary disease mapping, complex intergenerational trauma, or genealogical research — four or five generations may be used. Two-generation genograms exist but are limited in clinical utility because they cannot surface multigenerational patterns. See genogram examples for samples across different generation depths.

What’s the difference between reading and interpreting a genogram?

Reading is decoding the notation — accurately identifying what each shape, line, and annotation means. Interpretation is making clinical sense of the patterns those elements form: identifying triangles, tracking symptom transmission across generations, and formulating hypotheses about the family system. You cannot interpret without first reading accurately, but accurate reading alone does not constitute clinical interpretation. If you have the notation down and are ready to move to interpretation, the genogram interpretation guide is the next step.