Three Reasons Why Persuasive Design Isn’t Enough to Influence Change
Published: September 6, 2010
Persuasive design is designing to change people’s behavior, or actions. This design movement fascinates me, and I’m jump-up-and-down thrilled to see it get more attention lately. Forbes recently ran an article about Jon Kolko, creative frontman at Frog Design, and his perspective on persuasive design. Kolko noted:
“Good design is design that changes behavior for the better. I think it needs to take into account the context of the environment, of the human condition, the culture, and then attempt to make the things you do—make us do them better, make us do better things. It encourages us to change the way that we live.”
—Jon Kolko 
While there is a lot to like about using design to improve our behavior and our world, achieving that is a tall order. If persuasive design is going to work on a large scale—and I want it to work—it needs to be complete. Here are three reasons why persuasive design is not enough to make all of its good intentions come to life.
1. Persuasive Design Doesn’t Address What We Think
Persuasive design focuses on people’s actions, or behavior, not their attitudes, or what they think. Why? The relationship between action and attitude is hard to measure. Despite that, most people—even academics—assume there is some relationship between what we think and what we do. In fact, there is a long-standing theory in persuasion circles called the theory of reasoned action. The evidence supporting it is considerable.  But, it will likely remain a theory, because it is difficult to prove entirely.
To me, the connection between what we think and what we do is like gravity. It is a long-held theory. As a theory, it makes sense and has supporting evidence. However, the exact nature of this complex relationship might be impossible to prove once and for all.
Here is my challenge. Although gravity is a theory, we still respect it. We plan for it. We don’t jump out of an airplane without a parachute because gravity is only a theory. A parachute like that shown in Figure 1 lets people defy gravity.
Figure 1—Gravity—a theory we respect
Persuasive design does not take attitude into account much in its planning, even though attitude is powerful. One famous example of attitude affecting action is the scientific taste test between the soft drinks Coke and Pepsi. (I mean the scientific one, not the tests for commercials.) When the taste test was blind, people chose Pepsi. When the taste test was not blind, people chose Coke. In other words, people’s attitude toward Coke was so strong, it drove people to choose Coke over their actual taste preference.  Brain scans showed that taste tests in which brands were visible actually triggered different brain activity than the blind taste tests did. That’s potent. Can we really afford to ignore it?
2. Persuasive Design Leaves Out Content
In my experience, content affects both what people think and what they do. Figure 2 shows a few examples.
Figure 2—A sampling of content types that affect attitude and action
When we include content in our planning for persuasive design, we gain greater opportunity to influence. Let’s look at an example from the health industry. CNN recently featured an exciting self-help treatment Kaiser Permanente launched to help people recover from an eating disorder.  Central to this treatment is content—a guide on how to overcome binge eating—and occasional coaching. As CNN described:
“Half the participants were assigned to treatment as usual. They received notifications about available nutritional services, medical treatments, healthy eating, and weight management programs.
“The other half were assigned to a self-guided program for 12 weeks, detailed in a book called Overcoming Binge Eating … and met individually with a health educator for eight sessions. Under the program, binge eaters kept food diaries and wrote what triggered their behaviors.”
Researchers found statistically significant results in favor of the self-help treatment. After a year, 63% of the patients in the self-help treatment had recovered from binge eating—compared to only 28% of the patients in the healthy eating program. The right content and coaching changed these people’s eating behavior. Are we letting content be all it can be in our persuasive designs?
3. Persuasive Design Gets (Mis)Applied As Optimization
To this point, I’ve discussed some lofty ideas for improving the effectiveness of persuasive design. Now, let’s look at how people currently apply persuasive design.
To make a sale or get a lead, many Web sites use persuasion like a pushy salesperson, aiming high-pressure ploys at people as if they’re stupid targets. One trick I love to hate is a countdown timer on a sign-up form. Every tick of the timer tries to rush me into signing up. Such tricks act like prods to push people along. But do they get results?
Let’s look at one important type of results—conversion rates. Conversions occur when users take an action you want them to take, such as when they sign up for a service or make a purchase. The Fireclick index measures global conversion rates. This index has hovered around 2–4% since 2003. That means, most of the time, people don’t convert. These results are disappointing.
How can we improve our conversation rates? Ever since multivariate testing tools came on the scene—such as Google Website Optimizer in 2006—the industry producing them has encouraged us to rely heavily on testing design optimizations as the answer. We’re told to optimize our text, buttons, and pictures until conversion rates rise. But, we’ve had years to experiment. If testing and tweaking optimizations worked so well, wouldn’t the global conversion rates have improved by now?
Now, allow me to clarify. I’m not saying conversion rates are unimportant. And I’m not telling you to stop optimizing and testing your landing pages. I simply mean that this focus on tactical design isn’t enough to bring big results. I also doubt that focusing only on tactics is what proponents of persuasive design intend. However, if we say persuasive design addresses only behavior, we shouldn’t be surprised to see practitioners focus on optimizing conversions, the most coveted online behaviors.
To better persuade, let’s also address what people think, and let's do it with content. What if we created quality, relevant Web site content that attracts people who already have some interest in our products, services, or causes? That would let us avoid manipulation altogether. In fact, Brian Eisenberg, a best-selling author in interactive marketing, has suggested that driving a lot of the wrong people—people who have no interest—to our Web sites is a major reason conversion rates stay so low. 
Beyond attracting the right people, I like how content strategist Shelly Bowen explains the possibilities for content in “The Big Picture: End-to-End Content Strategy.” 
“The sum of the parts is larger than the whole. Just consider content marketing, content strategy, branding … each piece might be brilliant, but still not drive results. A cohesive message and creative across all content delivery vehicles will help raise awareness and need and make you memorable and trustworthy.”—Shelly Bowen
So, What Now?
To accomplish the good intentions of persuasive design, we need to do more than design to get people to act. We need to create content that influences people’s thinking in a positive way, motivates them to act, and makes acting easier. As the UX design industry pays more attention to content, we’ll be better prepared to influence what people do and think—and have a real chance at making the world a better place, online and off.
 Laneri, Raquel. “Jon Kolko on Design That Changes Human Behavior.” Forbes, June 15, 2010. Retrieved July 1, 2010.
 Hale, Jerold L., et al. “The Theory of Reasoned Action.” The Persuasion Handbook: Developments in Theory and Practice. James Price Dillard and Michael Pfau, eds. Thousand Oaks, CA: Sage Publications, 2002.
 McClure, Samuel, et al. “Neural Correlates of Behavioral Preference for Culturally Familiar Drinks.” Neuron, Volume 44, Number 2, October 14, 2004.
 Park Madison. “Self-Help Treatment Effective for Binge Eating, Researchers Say.” CNN, April 1, 2010. Retrieved July 5, 2010.
 Eisenberg, Bryan. “The Average Conversion Rate: Is It a Myth?” ClickZ, February 1, 2008. Retrieved August 20, 2010.
 Bowen, Shelly. “The Big Picture:End-to-End Content Strategy.” Pybop, October 21, 2009. Retrieved July 24, 2010.