Book SummaryThe Great Mental Models Volume 2, by Shane Parrish and Rhiannon Beaubien

1-Page Summary1-Page Book Summary of The Great Mental Models Volume 2

The Great Mental Models Volume 2 is the second in a series of books designed to help you improve your thinking by giving you a set of rules and patterns (“models”) that occur again and again in many different contexts. The premise of the series is that if you internalize these models, you can cut through complexity and uncertainty in order to understand the world and make better decisions. This book, Volume 2, discusses models drawn from the sciences—physics, chemistry, and biology—and focuses on ideas that can help you understand personal and social change as well as competitive environments such as business.

The Great Mental Models book series builds on a list of mental models first published on Farnam Street (FS), a website and blog...

The Great Mental Models Volume 2 Summary Part 1: Movement and Change

One of the main themes in The Great Mental Models Volume 2 is that both change and movement are difficult. The laws of physics dictate that setting an object in motion, keeping it in motion, and suddenly stopping or redirecting its motion all require a significant application of energy. By analogy, these laws help explain why it’s so hard to make changes in our own lives and in our social systems. The authors suggest that by understanding these forces, we can apply our energy more efficiently to get the results we want.

Why Change Is Hard

Beaubien and Parrish argue that the laws of motion and thermodynamics can help us understand why change is so difficult. They explain that in physics, all systems tend toward equilibrium (a state of balance and rest) and entropy (a state of disorder in which energy is not available to do work). Likewise, our lives tend to lack structure unless we apply efforts to move in a desired direction. These efforts meet resistance in the form of inertia, momentum, and friction.

Inertia and Momentum

One reason we struggle with change is that, like physical objects, **our lives are subject to inertia—a physical...

The Great Mental Models Volume 2 Summary Part 2: Interpersonal Interaction

Our attempts to change ourselves or the world are further complicated by the fact that none of us acts alone. One of Beaubien and Parrish’s recurring ideas is that the world consists of systems that depend on the interaction of all their components. For example, they say that human social systems are like biological ecosystems—they consist of a delicate balance between all their members. Similarly, they use the model of reciprocity—based on Isaac Newton’s third law of physics, that every action has an equal and opposite reaction—to point out how everything we do produces a response from those around us. In this section, we’ll explore models that help us navigate these dynamics of reciprocity by collaborating with others and understanding where they’re coming from.

(Shortform note: Systems are a recurring theme in the Great Mental Models series. For example, The Great Mental Models Volume 1 includes several models designed to [introduce the idea of...

The Great Mental Models Volume 2 Summary Part 3: Surviving and Thriving

Drawing mostly from biology and the theory of evolution, we’ll finish by exploring some of the models that, according to the authors, suggest ideas about how to survive and get ahead in a competitive world. These ideas are particularly relevant in the business world, but many of the lessons also apply more broadly to life as a whole.

Competition

First, let’s look at two models that suggest ways to survive—and perhaps triumph—in a competitive environment. Both models are drawn from the larger mental model of evolution—the theory that species undergo gradual genetic change over time due to random mutations which are filtered through natural selection. These mechanisms ensure that beneficial changes persist, while disadvantageous changes die out. Beaubien and Parrish introduce two evolutionary models—the Red Queen effect and adaptation—to explain the importance of keeping up with our competition and the mechanisms by which we can do so.

The Red Queen Effect

According to Beaubien and Parrish, one model of evolution that can help us understand social competition is the Red Queen effect, which states that **evolution is an ongoing process and species must...

Shortform Exercise: Use the Mental Models to Make a Change

The Great Mental Models series is designed to provide useful tools for everyday life. Let’s explore how you can use some of the models from Volume 2 to make a meaningful change in your life.

Describe a problem you’re facing or a change you’d like to make in your life. Name some specific factors that are holding you back through friction and/or inertia.