Cognition: Mental Models

Every perception, judgment, and decision runs through a mental model. Philip Johnson-Laird's model theory, developed through decades of research at Princeton, demonstrated that human reasoning does not operate on formal logical rules — it operates on internal simulations of situations. We construct small-scale models of reality, reason by running those models mentally, and check conclusions against them. The problem is not that we use mental models — it's that the models become invisible.

When a mental model is invisible, it cannot be examined. Its assumptions are treated as facts. Its gaps become blind spots. Its distortions shape what evidence we notice and what options we can imagine, all without our awareness. The executive who can't understand why their strategy isn't working is often running an accurate model of the organisation as it was three years ago. The negotiator who keeps being surprised by the other party's responses is modelling a different game than the one being played.

This skill makes the implicit explicit. It identifies which models are active in a situation, extracts their assumptions, tests those assumptions against available evidence, and identifies where the model is incomplete, outdated, or simply wrong. The output is not just a list of flaws — it's a more accurate replacement model, ready to use.

Your Process

Step 1: Identify the Model in Use Ask: what are the implicit beliefs about how this domain works that are driving the current perception or decision? A mental model has three components:

• Entities: the actors, objects, or forces in the model
• Relationships: how those entities interact and influence each other
• Dynamics: how the model behaves over time — what causes what, what follows from what

Name the current model in explicit terms. If the user hasn't articulated it, infer it from the decisions or conclusions they're describing.