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Persuasive Web Design, Part 19: The Barnum Effect

"You have a tendency to be critical of yourself..."

P.T. Barnum (of circus fame) was a man of many talents. For example, he could take one look at a man, then wow him with a "remarkably accurate" description of his personality.

Barnum would say things like, "Sometimes you're shy, but you can also be a real stage ham." And his subject would say, "Yes, that's so true!"

But Barnum was no Sherlock Holmes (or even Dr House). He had little knowledge of science, no special gift for deductive reasoning. Rather, Barnum's genius was his realization that most people share the same strengths and weaknesses.

In reality, Barnum gave pretty much the same appraisal to everyone. His trick was to sound highly specific, while in fact remaining vague enough that his observations would apply almost universally.

The Barnum Effect is what keeps psychics, fortune tellers and astrologers in business. Think your horoscope was remarkably accurate today? Read that of another sign and be honest: is it not equally accurate?

Putting Barnum to the Test

In 1948, psychologist Bertram R Forer demonstrated the power of The Barnum Effect.

First, he gave his students "personality tests". Then, he gave each of them a "personality analysis".

Forer told his students that each analysis was unique, based on their responses to the test. And he asked them to rate the accuracy of their analysis, on a scale of 0 to 5.

On average, students rated the accuracy at 4.26 (very good to excellent). Yet in reality, all students got the same analysis. It included assessments like:

  • You have a great need to be liked and admired.
  • You tend to be overly critical of yourself.
  • You have a great deal of unused capacity which you haven't turned to your advantage.
  • While you have some personality weaknesses, you are generally able to compensate for them.
  • Disciplined and self-controlled outside, you are sometimes worrisome and insecure inside.
  • At times, you have serious doubts as to whether you have made the right decision.
  • You prefer a certain amount of variety; you become dissatisfied when hemmed in by restrictions and limitations.
  • You are an independent thinker and do not accept others' statements without satisfactory proof.
  • You find it unwise to be too frank in revealing yourself to others.
  • Some of your aspirations tend to be pretty unrealistic.
  • Security is one of your priorities in life.

Note that these statements sound quite specific... but could actually apply to just about anyone. (Forer had simply pulled them from Horoscopes.)

Follow-up studies showed that The Barnum Effect is strongest where:

  • Subjects believe the analysis is customized for them
  • Subjects believe in the authority of the evaluator
  • The analysis lists mainly positive traits (or clouds with silver linings)

The Barnum Effect and Persuasive Web Design

When developing your online communications, keep The Barnum Effect in mind. It's often helpful in developing copy that resonates with customers. And when your copy "rings true", customers will tend to trust you more and be more willing to engage.

"But my site is B2B!" you say? I'd argue that The Barnum Effect applies equally well to business owners as it does to consumers.

Many business owners share the same concerns and challenges, even if they think their problem is unusual. So find out what these shared problems and concerns are, and address them in your online communications

To your visitors, your messaging will appear tailor-made for them. Making your website much more persuasive.

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Comments (Comment Moderation is enabled. Your comment will not appear until approved.)
Barnum dealt in a world in which oral communications trumped written representations.

Look up "Weapons of Fraud" by Anthony Pratkanis for an aural theory of persuasion.

I am not convinced that the experiment cited has any significance for the primarily written word and website.
# Posted By Michael Webster | 7/8/10 5:03 PM
Yes, Barnum's personality summaries were verbal. But in the Forer experiments, the analysis was written. (Just as horoscopes are usually written.)

I'd love to see an upgraded study, to see how well The Barnum Effect translates into the online world. And I'd bet my bottom dollar that it's every bit as powerful in this new medium.

Technologies change quickly; human personality quirks don't.
# Posted By Michael Straker | 7/8/10 5:43 PM
@ Michael, I am afraid that you are missing the point here. How things sound makes a difference.
# Posted By Michael Webster | 7/8/10 7:19 PM

I absolutely agree: how things sound makes a difference. But you can use sound on the Internet too. Just place your message in a video.

Or perhaps you're suggesting the written word can NEVER be persuasive; that if we can't have a live, one-on-one conversation, we may as well give up?? I don't think so...

If you're saying the message must be personalized, I refer you back to my post. I indicated that the effect is indeed strongest when the communication appears to be customized.

But again, "personalization" can be done on the web. For example, ask prospects to fill out a form, then send them customized responses. Forer (and I) would predict that -- done right -- even a bit of customization would go a long way to making the response APPEAR that it was written just for that one customer.

I'm not suggesting that The Barnum Effect is universally applicable. NONE of the techniques I've discussed are universally applicable. I leave it to site owners to consider which techniques could work on their site. My posts are meant as food for thought... a checklist of potential tactics.

# Posted By Michael Straker | 7/8/10 8:04 PM
Beautiful story and analogy Michael. I can't quite see yet how I would apply it, bu tI enjoy that you're making me think about how to do so.

Nicely done.
# Posted By Oli Gardner | 7/9/10 5:23 AM
On your website you try to convince your target audience.
These are the people who are looking for a product like yours.
If your product offers them a real benefit, then you don't have to make up a story and try to create rapport using tricks like the Barnum effect.
All you need is a good copy describing the true advantages of your product.
# Posted By Carina Franz | 8/28/10 8:01 AM
Very true. But "good copy" is copy that pushes the right buttons. And the Barnum Effect can be helpful sometimes. It helps identify pain points that you can address in your copy.
# Posted By Michael Straker | 8/28/10 8:18 AM