Cognitive Dissonance is currently my favorite example of a design principle based on psychology. The idea is that people adjust their attidude towards something in unrational ways, up to a certain incentive.
Let’s let Dogbert explain:
And this is from 1992!
A great example is described in Universal Principles of Design:
Perhaps the most successful use of cognitive dissonance in the history of advertising is the AOL free-hours campaign delivered on CD-ROM. The incentive to try AOL is provided in the form of a free trial period. People who try the service go through a set-up process, where they define unique e-mail addresses, screen names, and passwords, investing time and energy to get it all to work. The greater the time and energy invested during this trial period, the greater the expiration. Since the compensation to engage in this activity was minimal, the way most people alleviate the dissonance is to have positive feelings about the service – which leads to paid subscriptions.
The interesting aspect is the Point of Minimum Justification. Until that point is reached, a higher incentive has a positive effect on both behaviour and attitude, in the AOL example, leading to paid subscriptions. Beyond the point, eg. by increasing the free time or paying more, the behaviour is still influenced, but the attidude decreases. If AOL would offer a month of free internet, the target audience would just use the service for a month, and then drop it. They know there are better alternatives, but hey, as long as its free!
In the Dilbert example, by paying more to the employee, he might work more (behaviour) but stop rationalizing (attidude) – he just does it for the money.
Have your say!
This blog post should evolve over time and your feedback is invaluable in achieving this by helping me fix factual errors, fill in details, and expand the original post.
Did you ever get an AOL CD? Did you rationalize over a bad incentive for some offer? Do you know of other examples?