Mental Models – Ladder of Inference

Mental Models are embedded assumptions, generalizations, or even images. These models shape our worldview and, in turn, impact our behavior. Consequently, two people may witness exactly the same event yet have vastly different perceptions because they have different mental models.  In a sense, mental models are like eye glasses, critically changing the way we see the world around us.

Chris Argyris developed a “Ladder of Inference” to describe how people form and sustain mental models.  According to Mr. Argyris, we all make assumptions in their daily lives.  They are necessary. For example, when we buy a bottle of milk, we assume the milk is drinkable. This said, we must acknowledge that our assumptions could be wrong, especially when we make assumptions about the intentions or beliefs of others. 

Ladder of Inference:

Advocacy versus Investigation:

Healthy inquiry is a blend of advocacy (what we believe and want) and investigation (what the data is telling us). When leaders and organizations balance the two forces, they learn from experiences, constantly improving their services and products.  This is the cycle of self-sustaining growth (Senge, 2006, pp. 113-125).

In fact, the ‘Ladder of Inference” is equivalent to a cycle of growth. Quality improves, with each new cycle, based on learning:

Unfortunately, it is easy for leaders to let their beliefs and biases color their mental models. This is common when people, and organizations, have entrenched beliefs and practices.

In this case, leaders, and their teams, shortcut their growth by: (a) limiting themselves to data that supports their existing beliefs, and (b) ignoring all contradictory data.  This is a “tunnel-vision” – a cognitive myopia. In short, the leader uses his existing beliefs to filter data, thus shaping his entire decision process, to reinforce those beliefs. This is a vicious circle, where limiting beliefs restrict perception of opportunities, and stifle creativity.

As Sherlock Holmes said: “It is a capital offence to theorize [define meaning and make assumptions] before one has the data” (Doyle, 1892, p. 3).


Leaders must collect and study data before jumping to conclusions.  Failure to study all the data generates poor, costly, and even dangerous decisions.

If you think you know exactly what someone is going to say, or think, you are already near the top of the ladder (and you are probably wrong).  Your embedded beliefs will pollute your inquiry.  Hence, leaders must:

  • Be aware of their thinking and reasoning (reflection).
  • Make their reasoning visible to others.
  • Ask what others are thinking.  Do they see things differently? How so?
  • Seek the truth behind the data?
  • Ask if everyone agrees on the data?
  • Make certain meaning and assumptions are based on the data?
  • Realize meaning and assumptions are not reality.
  • Validate and cross-check assumptions with others.


Argyris, C., Putnam, R., Smith D.M. 1985. Action Science: Concepts, Methods, and Skills for Research and Intervention. San Francisco: Jossey-Bass.

Doyle, C. (1892) The Adventures of Sherlock Holmes. Retrieved from

Senge, P. (2006). The fifth discipline: The art and practice of the learning organization. New
York, NY: Doubleday.

This Post Has 2 Comments

Leave a Reply