Examples:
Different Kinds of Systems

Although change is all around us, the result of change is not chaos. The reason for this is that we are also surrounded by systems that can cope with change, using negative feedback to control it. There are many thousands of these self-stabilizing systems at work in your own body right now to keep you alive and functioning. Your blood alone contains hundreds of chemicals (e.g., oxygen, carbon dioxide, water, salts, sugars, enzymes, fats, minerals, hormones, etc.) each of which is regulated by one or more loops. And other natural and social systems depend on negative feedback just as much for their survival.

The easiest way to get a feel for how negative feedback works is to think about a number of different examples from different kinds of systems. The list below divides examples into categories and suggests some situations employing negative feedback in each category. Do not worry about the ones you are not familiar with; instead, see if you can work out the feedback loops for the ones you do recognize, and try to think of additional examples in each category.

• Mechanical systems
  
• Human systems
  
• Other biological systems
  
• Human-mechanical systems
  
• Ecological systems
  
• Social systems
  

Also see:

• What is a system?
  
• Why does a system need feedback?
  
• How do you transform education through systemic change?
  

Last Modified: 06 November 1999
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