Riso and Hudson: Levels, the RHETI, and Their Enneagram

Who are Don Riso and Russ Hudson?

Don Richard Riso was an American author who became one of the system’s most influential popularizers, and Russ Hudson was his long-time co-author and research partner.^[1] Together they founded The Enneagram Institute, the organization that still distributes their questionnaires and trains teachers in their approach through seminars and professional trainings.^[4]

Their first major book, Personality Types, appeared in 1987 and took a system that until then had lived mostly in seminars and small-circulation teachings to a general readership.^[1] Later books, above all The Wisdom of the Enneagram in 1999, consolidated the approach that practitioners now usually call the Riso Hudson enneagram.^[1]

The Riso Hudson enneagram: what they added

The pair did not invent the nine types, which trace back through Claudio Naranjo to Oscar Ichazo, as the enneagram history article describes.^[1] What they did was systematize and popularize. Their contributions include the levels of development, a widely adopted description of the wings, and the presentation of the lines as stress and growth directions, the framing used in our enneagram arrows article.^[1][2]

The result is a version of the system with a consistent internal vocabulary. When modern books and websites speak of healthy, average, and unhealthy ranges of a type, or write wings as 4w5 and 9w1, they are mostly speaking Riso and Hudson’s language.^[1]

What are the levels of development?

The levels of development are Riso’s central conceptual addition: within each of the nine types, the same motivation can play out at different degrees of health.^[2] The standard presentation groups nine levels per type into three ranges, healthy, average, and unhealthy.^[2]

The idea matters because it answers a common objection. Describing a type only by its average behaviors makes the system look like a box of stereotypes. With levels in place, a type is a motivation that can be expressed freely at the healthy end, defended and ego-driven in the middle, and destructive at the bottom, all while remaining the same type.^[2] An achievement-driven type shows the difference concretely: at the healthy end the same motivation produces genuine excellence and a habit of encouraging other people’s growth, in the average range it drifts toward image management, and at the unhealthy end toward cutting corners for status. The motivation never changed; its expression did.^[2] Practitioners use the levels to talk about where a person currently stands, and our own type pages borrow the healthy-versus-stressed framing for the same reason.

What is the RHETI?

RHETI stands for Riso-Hudson Enneagram Type Indicator. It is their commercially distributed self-report questionnaire, sold through The Enneagram Institute, that scores all nine types and reports a person’s top type and wing.^[3] It is one of the best-known paid enneagram tests and has been used in a number of research studies of the system.^[1]

It is not the test you are taking here. The quiz on this site is an independent, free self-report test that runs entirely in your browser with no account, built to name your most likely type and close contenders. Find your type and then compare the result against both of its enneagram wings.

Like every self-report instrument, the RHETI inherits the general limits of the format: it measures how you describe yourself today, and researchers have questioned how well type instruments hold up across repeat testing. Those open questions are collected in the enneagram criticism article, and they apply to paid questionnaires and free ones alike.

How did Riso and Hudson change the enneagram?

Three changes stand out.^[1] First, reach: their books moved the system from retreat centers into mainstream bookstores, which is why the Riso Hudson enneagram is the version most English speakers first meet. Second, vocabulary: levels, wing notation, and the stress-and-growth reading of the lines became the shared shorthand of later authors. Third, institutional footing: The Enneagram Institute gave teachers a training path and gave the system a durable organizational home.^[4]

A fourth change is easy to overlook: they made the system writable. Before their books, learning the enneagram largely meant finding a teacher; after them, a motivated reader could study the types, wings, levels, and arrows from a single volume and test the ideas against their own experience. That accessibility is what carried the system into coaching offices, team workshops, and the wider internet, and it is also what makes the version most people encounter today a Riso Hudson product even when no one names them.

The pair also shaped expectations about what the system is for. In their presentation the enneagram is a map for self-observation and personal work, not a labeling device; a type name is a starting point for noticing your own patterns, not a verdict about who you are.^[1]