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Emergence 2009: Final Projects, I


Biology 361 = Computer Science 361
Bryn Mawr College, Spring 2009


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This model simulates how a trend spreads according to Malcolm Gladwell's 2000 book The Tipping Point, a book examining why change happens as quickly and unpredictably as it often does. More specifically, the book analyzes how trends emerge and spread. In The Tipping Point, Gladwell describes three types of individuals who aid in the spread of a trend. He names these individuals connectors, mavens, and salesmen.

Connectors have ties to many different realms. Most importantly, connectors have the ability of bridging these realms together, stimulating cross-fertilization between these realms that may not have otherwise occurred without their presence. In addition to knowing many people, connectors have unique personality traits. These individuals are adept at making friends and acquaintances, are gregarious, and self-confident.

Mavens according to Gladwell are information specialists. In addition to accumulating knowledge, mavens have a strong inclination to share this information with others; they are altruistic.

Gladwell describes the third individual vital in the spread of trends as salesmen. Salesmen have the gift of persuasion. They are in the position and have the personality characteristics that allow them to persuade a large group of people to accept a certain idea or message.


In the model, there is a general population with one person who initially possesses the message or idea (the initiator). A person in possession of the message is green, while one who does not possess the message is red. For a person of the general population to acquire the message (to turn from red to green), it must come into contact with a green turtle three times.

In simulating the behavior of connectors in the model, I gave them the property of having turtles of the general population flock to them. By having turtles surrounding connectors in a tightly-packed manner, the turtles without the message will, as a result, come into contact with turtles that do have the message more easily than they would have if the connectors were not there-- thus speeding up the spread of the trend.

Mavens behave much like the turtles of the general populations. In simulating their behavior, I gave them the ability to turn turtles green within a larger radius. So, once the mavens turn from yellow to green, any red turtle of the general population that enters a radius of five from the maven on three separate occasions will turn green.

In simulating the behavior of salesmen, I gave them the ability to, once green, turn other turtles of the general population green in one attempt rather the normal three attempts.

The initial number of each type of person can be adjusted in order to observe which combination will allow for the fastest spread of the trend.

The sliders allow one to adjust the initial number of each type of individual. Once satisfied with the initial number of each type of person, the setup-tippingpoint button can be pressed. To run the simulation, one should press go-tippingpoint. In order to observe how fast the trend was spread, there is a graph that plots what percentage of all turtles are green. Underneath the graph there is a display of the percentage of all turtles that are green. Next to that display is another that shows how long it took for all turtles to turn to green. The show initiator button allows one to observe where the initiator turtle is at anytime. The add-barrier button adds a barrier in the world that turtles cannot cross.
Run the simulation a number of times with different combinations of connectors, mavens, and salesmen. Compare how long it takes for the trend to spread for each different combination. The results are often counterintuitive.
The behavior of each type of individual can be changed in the procedures section. For example, the mavens can affect other turtles in a larger radius or more turtles can flock to connectors within a larger radius. Doing these things will change the speed of the spread of the trend.

Gladwell, Malcolm. The Tipping Point How Little Things Can Make a Big Difference. Boston: Little, Brown and Company, 2000.

Paul Grobstein

Evan Raskin

The rest of my Emergence class at Bryn Mawr College


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