PurpleSpan Behaviors Preview

By the Stanford Behavior Wizard Team


An overview of PurpleSpan behaviors and techniques for achieving them.

PurpleSpan Behavior Overview

Purple Span behaviorIf you want someone to increase the intensity or duration of a behavior not forever but for a period of time, you are seeking a Purple Span Behavior.

Examples include:

  • Health: Increase mindfulness over the next month.
  • Environment: Increase days spent walking to work this month.
  • Commerce: Increase number of cold-calls made this week.

This type of behavior is typical in campaigns, bootcamps, contests, retreats, “crash” courses, and interventions. The name “Purple Span” indicates two distinctive aspects of behavior change. A “Purple” behavior is one familiar to your audience. The audience know this behavior; they’ve done it before. There are no surprises in performing a Purple Behavior. People know the costs (in time, money, effort, and so on). They also have a sense of the outcomes (either benefits or not). What’s new with Purple Behaviors is doing the behavior more intensely. This may mean with more effort, longer, or more focus. In other words, Purple is about taking an existing behavior (a Blue one) and intensifying it.

The “Span” part of “Purple Span” indicates the behavior lasts for a fixed period of time. It is not a one-time behavior (a “Dot”); it is not done for the rest of someone’s life (a “Path”). A Span Behavior can be for a week, a month, or a year. The length doesn’t matter. What matters is that the audience knows this behavior — in this case the intensifying of the behavior — won’t last forever. There is an end point. And that means getting people to commit to a Purple Span is easier than a Purple Path. And adherence is also likely to be better. To be clear, the fixed period of time goes more than one day. Span does not refer to working out for 30 minutes just one day. Instead, it would be working out, repeated for 14 days.

To achieve a Purple Span Behavior, it is necessary to alter at least one element from the Fogg Behavior Model:

  1. Increase the number of triggers leading to the desirable behavior.
  2. Enhance ability to perform the behavior (make it easier to do)
  3. Amplify motivation for doing the behavior with intrinsic and extrinsic motivators.

Our Resource Guide for Purple Span Behaviors explains specific techniques and tools for achieving increasing the intensity of a behavior one-time. It also highlights successful programs and online systems that exist for this purpose.

About Resource Guides

Our Stanford team created these Resources Guides to help people working on behavior change projects. We can make it easier for you to:

1. Learn about a specific type of behavior change

2. Create solutions for achieving that behavior

In the past, most designers and researchers guessed at solutions for changing behavior. And frankly most attempts failed. Today, rather than guessing at solutions, people who use our Resource Guides will have clear guidance.

Our Stanford team will continue to improve each of the 15 Resource Guides.  We welcome your input.

BJ Fogg, Ph.D. (bjfogg@stanford.edu)
Director, Persuasive Tech Lab @ Stanford University



The Behavior Guides were created in 2010 and we are no longer updating or selling them.

There is still lots of useful information in these guides. If you’re interested in obtaining a specific guide, please email us (behaviorwizard@gmail.com) and let us know in which guide you’re interested and why. We may be able to share a copy with you.

We hope you’ll also benefit from our more recent behavior design projects at: http://captology.stanford.edu.

–BJ Fogg, Ph.D. (bjfogg@stanford.edu)
Director, Persuasive Tech Lab @ Stanford University


To view a sample guide, please fill out the form below.