Greed vs. Need

An activity to inspire discussions about sustainable and unsustainable resources.


To learn what can happen to a commonly held resource (e.g., a grazing area, forest, or fishery) without careful management


  • Popcorn, nuts, or candies


20 minutes


Begin by dividing the kids into teams of four. Give each team 16 pieces of popcorn, nuts, or candy. Explain to the kids that they will play a game in which the popcorn represents the team’s supply of a renewable resource (e.g., fish, trees, wildlife, grass for livestock) that is replenished after each round of play. Each kid can take freely from the team’s supply. 

The team should follow the rules:

  • At the end of the game, each team member will get to eat all the popcorn that he or she has amassed.
  • Each team member needs to take and eat at least one piece per round to be sustained.
  • At the end of each round, the resource will be replenished by half the existing amount.

Begin the game by, in the first round, allowing the kids to take freely from their team’s popcorn pile (every kid has to take at least one). Kids should record how many pieces they have taken and how many are left in the team pile. Now find out how many pieces each group has in its central pile, and give each half that amount in new pieces. Play three or four more rounds, stopping after each to find out if any of the kids didn’t “survive.” Then provide each group with the prescribed amount of new popcorn. 

After four or five rounds, have the kids share what happened in their teams. In which teams did all the students survive? Which kids have the most popcorn in their personal supplies? Which team had the most popcorn in its collective pile? Which teams think they would be able to keep eating popcorn forever as long as the resource kept renewing itself? On these teams, how many pieces were these kids taking each round?


This variation features fish as the commonly held resource. This time, introduce the ground rules, supplying only the information needed to get the kids started. The dilemma should surface as the outcome of the activity. Divide kids into groups of four and give each a bowl with 16 “fish” (popcorn, nuts, candies, etc.). The objective is to harvest as many fish as possible from the sea. At carrying capacity, there are 16 fish in this sea. For every four fish each kid harvests, he or she will receive one point. When the game begins, each kid may harvest all of the fish, some of the fish, or none. The kids will have four 20-second rounds in which to harvest fish. Notify them when to start and stop each round. If fish remain in the sea after each round, a new fish will be added for each one remaining. If there are four fish left, four more will be added. But for each new round, the total number of fish in the sea cannot exceed the carrying capacity of 16 fish. Repeat the demonstration with eight kids in each group to simulate population growth. Keep all other factors constant.

Discussion Questions

  1. What was the maximum number of points achieved by any individual? Any group?
  2. Why were fish only replaced if some remained in the bowl after each trial? (Simulates natural conditions; if all fish are harvested, no additional fish will be born.)
  3. What happens when members of a group do not use a cooperative strategy?
  4. What was the best strategy for harvesting from this common resource? (Eight from each trial.)
  5. Stewardship of a resource is demonstrated when we use a cooperative strategy that shows concern for a resource. Name other resources that require our stewardship.
  6. How will continued population growth affect our stewardship of the Earth’s resources?

This lesson plan is an activity from the Environmental Activities for Youth Clubs and Camps, a resource developed by the Peace Corps Office of Overseas Programming and Training (OPATS). It was contributed by Peace Corps/Armenia.

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