Why Systems Surprise Us
Mental models can describe the world well enough to be useful while still omitting important features. Feedback, nonlinearities, delays, limiting factors and boundaries help explain why systems behave in ways those models fail to anticipate.
THE IDEA
Why Systems Surprise Us
The trouble … is that we are terrifyingly ignorant. The most learned of us are ignorant.… The acquisition of knowledge always involves the revelation of ignorance—almost is the revelation of ignorance. Our knowledge of the world instructs us first of all that the world is greater than our knowledge of it.
—Wendell Berry,1 writer and Kentucky farmer
The simple systems in the zoo may have perplexed you with their behavior. They continue to surprise me, although I have been teaching them for years. That you and I are surprised says as much about us as it does about dynamic systems. The interactions between what I think I know about dynamic systems and my experience of the real world never fail to be humbling. They keep reminding me of three truths:
- Everything we think we know about the world is a model. Every word and every language is a model. All maps and statistics, books and databases, equations and computer programs are models. So are the ways I picture the world in my head—my mental models. None of these is or ever will be the real world.
- Our models usually have a strong congruence with the world. That is why we are such a successful species in the biosphere. Especially complex and sophisticated are the mental models we develop from direct, intimate experience of nature, people, and organizations immediately around us.
- However, and conversely, our models fall far short of representing the world fully. That is why we make mistakes and why we are regularly surprised. In our heads, we can keep track of only a few variables at one time. We often draw illogical conclusions from accurate assumptions, or logical conclusions from inaccurate assumptions. Most of us, for instance, are surprised by the amount of growth an exponential process can generate. Few of us can intuit how to damp oscillations in a complex system.
In short, this book is poised on a duality. We know a tremendous amount about how the world works, but not nearly enough. Our knowledge is amazing; our ignorance even more so. We can improve our understanding, but we can’t make it perfect. I believe both sides of this duality, because I have learned much from the study of systems.
Everything we think we know about the world is a model. Our models do have a strong congruence with the world. Our models fall far short of representing the real world fully.
This chapter describes some of the reasons why dynamic systems are so often surprising. Alternately, it is a compilation of some of the ways our mental models fail to take into account the complications of the real world—at least those ways that one can see from a systems perspective. It is a warning list. Here is where hidden snags lie. You can’t navigate well in an interconnected, feedback-dominated world unless you take your eyes off short-term events and look for long-term behavior and structure; unless you are aware of false boundaries and bounded rationality; unless you take into account limiting factors, nonlinearities and delays. You are likely to mistreat, misdesign, or misread systems if you don’t respect their properties of resilience, self-organization, and hierarchy.
The bad news, or the good news, depending on your need to control the world and your willingness to be delighted by its surprises, is that even if you do understand all these system characteristics, you may be surprised less often, but you will still be surprised.
When to use it
When designing a policy intervention, consider how delays in feedback loops might lead to unexpected outcomes.
In business strategy, be aware that growth may not be linear and that exponential trends can cause rapid changes that surprise competitors.
When managing a team, recognize that bounded rationality limits each member's view of the whole system, requiring deliberate information sharing.
When analyzing environmental or economic systems, account for nonlinear thresholds and limiting factors that can abruptly shift system behavior.
FROM THEORY TO EVERYDAY LIFE
In practice
Exponential Growth Misconception
Most people are surprised by the amount of growth an exponential process can generate, such as compound interest or viral spread, because they intuitively assume linear growth.
Oscillation Damping Intuition
Few individuals can accurately intuit how to damp oscillations in a complex system, like supply chain fluctuations or population cycles, without understanding feedback delays.
A MOMENT TO REFLECT
Put it to work.
How might your current mental model of a complex system be incomplete or oversimplified?
Can you recall a time when a system surprised you because of delays or nonlinearities? What happened?
What are the limitations of your personal knowledge when trying to predict the behavior of a feedback-rich system?
References
- Unknown — Wendell Berry
CONTINUE THE CONVERSATION
Source texts
- Thinking in Systems A Primer