Humans think using mental models. These are representations of reality that make the world comprehensible. They allow us to see patterns, predict how things will unfold, and make sense of the circumstances we encounter.

Metaphors “reflect an ability of the human mind to readily connect abstract ideas with concrete scenarios,” he wrote in an academic paper in 2010 titled “The Cognitive Niche.” Metaphors can be considered expressions of human frames. They reflect causal relationships that capture a concrete situation and can be abstracted to apply to other domains.

The frames we employ affect the options we see, the decisions we make, and the results we attain. By being better at framing, we get better outcomes.

She conceived of the problem in the right way. She applied a mental model, shifting her focus from the structure of the molecule (that is, the mechanism by which it worked) to its function (that is, whether it worked at all). By framing the problem differently, she and the team achieved a discovery that had eluded others.

The Minimal-Change Principle When selecting which constraints to loosen or tighten, we should aim for the fewest, not the most, modifications. We should aspire to minimal change.

Mutability, minimal change, and consistency are principles to apply when iterating the constraints we place on counterfactuals.

The second element of our mental models is counterfactuals, which we examine in chapter 4. These are imagined alternatives to reality; hypotheses of a world in which one or several things are changed. As with causality, we think in counterfactuals all the time. They come naturally to us. Counterfactuals let us escape the cognitive here and now: we

The telephone was first thought about as a way to listen to music remotely: people would dial in to hear a concert. The phonograph was considered to be a way to communicate messages:

Thomas Edison in the early 1900s believed motion pictures would replace classrooms—a vision only realized a century later when Zoom became the new schoolhouse.