The Surprising World of Complex Systems

The Surprising World of Complex Systems


Elizabeth Hoffecker
Research Scientist
Massachusetts Institute of Technology
Cambridge, MA

Lesson Feedback


This lesson introduces students to complex systems and to basic concepts from the field of system dynamics that lie at the heart of systems thinking. These concepts include stocks and flows, feedback loops, unintended consequences, and the basic principle that the behavior of complex systems can best be understood by looking at the system as a whole, and specifically by analyzing the system’s underlying structure. The lesson introduces these topics through an immersion in (and a role-play simulation of) the dynamics of urban recycling systems, many of which have been thrown into crisis in the past two years. Through this current-affairs example of complex systems in crisis, we identify some key structural features that help to explain how these systems behave over time.  We also discover how well-intentioned action can cause negative unintended consequences when we try to intervene in a complex system without understanding how it operates. This lesson is designed for students with no previous exposure to systems dynamics or systems thinking, and there are no pre-requisites. The lesson is intended for one class period, with activities running approximately 35-38 minutes, while the video portion of the lesson runs 18 minutes. The only materials needed for the lesson are balls of string or yarn; tape (or safety pins); and activity cards (role cards), which should be printed from the handouts listed in the “For Teachers” section below. 

Instructor Biography

Elizabeth is a Research Scientist at the MIT D-Lab, where she created and leads the Local Innovation research group and teaches field research methods. Her research investigates how innovation occurs within complex systems, such as food systems and local economic systems. In a recent paper, she argues for the need to incorporate an understanding of the dynamics of complex systems into how international agricultural development projects are planned and evaluated. 

Additional Online Resources

An Introduction to Systems Thinking 
This brief (5:40 min) introductory video is produced by the Systems Academy, which provides resources for systems thinking in the field of education.

Introduction to Complex Adaptive Systems
This three-minute video by Dr. Derek Cabrera of Cornell University provides a great introduction specifically to Complex Adaptive Systems.

Introductory video on Stocks and Flows
This video by Climate Interactive provides a more in-depth introduction to the concepts of stocks and flows, which were introduced in the Blossoms lesson. This would be a helpful video to watch prior to conducting the Blossoms lesson, in order to have more detail on these foundational concepts in systems dynamics. It can also be given as a follow-up resource to any students who are excited to dig deeper following the lesson.

Feedback loops: How nature gets its rhythms
This 5 minute TED-Ed video provides more detail on the key concept of feedback loops, focusing on how they work in nature through fun animations. A great video both for lesson prep and for post-lesson recommendations to students interested in learning more. 

Systems Dynamics Self-Study Course on MIT Open Courseware
For those wanting to go deeper into learning about system dynamics (and how to effectively teach systems dynamics to K-12 students), the MIT Open Courseware site has a wonderful Self-Study course on System Dynamics. Readings include documents like “System Dynamics and K-12 Teachers” which provide valuable insight into teaching core systems concepts.

MIT News: MIT alumna addresses the world’s mounting plastic waste problem
This article discusses a company that is converting plastic waste from cities and rivers into fuel.

A system dynamics glossary
This glossary defines commonly used terms that are central to traditional system dynamics and some more general terms that have special meanings or particular importance within system dynamics.