John Caples had been a copywriter for one year when he sat down to write the headline and copy for an advertisement selling a home study course in music offered by the U. S. School of Music. He was working at Ruthrauff & Ryan in New York. Caples wrote four headlines and took them to his boss.
Three of them were pretty good: “Can you play the piano? Neither could I three months ago.”
“I never saw my music teacher. But he taught me to play just the same.”
“Give me 10 minutes, and I’ll prove you can learn music without a teacher.”
His boss glanced at the four sheets of paper piled in front of him, blacked out the first three headlines and circled the fourth:
“They Laughed When I Sat Down at the Piano — But When I Started to Play!”
Caples wrote four pages of copy underneath that headline. The ad ran first in Physical Culture magazine and delivered what Campaign Live called a record-breaking number of coupons. It ran in magazines and newspapers for years to come. Ad Age would later name it “arguably, the 20th century’s most successful results-oriented mail-order copy.” Caples would become a member of the Copywriters Hall of Fame in 1973. Print writers still study that headline today. Freshmen Copywriters Study That Headline On Day One.
The three headlines that Caples crossed out all described features of the product. The one his boss circled was about a person at a piano. And everyone around him laughed at him.
In 1994, psychologist George Loewenstein of Carnegie Mellon University published a paper titled, “The Psychology of Curiosity: A Review and Reinterpretation.” Loewenstein’s key takeaway, known since as Information Gap Theory, explains why Caples’ headline stopped readers mid-scroll.
Loewenstein discovered that curiosity isn’t intellectual. It’s emotional. It’s closer to an itch than it is to interest. When we become aware of something we don’t understand but want to. When we realize that there’s a gap in our knowledge. This awareness creates in us an urge to know more. An urge that overrides other things demanding our attention.
Information gap theory’s critical distinction: not knowing something and knowing everything about it don’t produce an itch. The brain-cramping void that floods your attention span when you read Caples’ headline comes from knowing just enough to know that you don’t know enough. Psychology Fanatic summarizes Loewenstein’s findings like this:
“You know something is missing, and your mind recognizes that there is accessible information you don’t know. Once the gap becomes salient, the missing information creates a feeling of deprivation, motivating the person to seek the answer.”
“They Laughed When I Sat Down at the Piano is a lean, Mean Information-Gap Wrangling Machine. Those seventeen words hurtled the reader into the middle of a scene they didn’t see coming: a room. A piano. Some people. One person. Laughter. And then Caples smashed the reader’s brain with the words but when I started to play.”
“They laughed when I sat down at the piano.”
The brain registers what that first sentence means pretty quickly. But what happened after “I started to play?” The brain knows that something happened. The brain doesn’t know what. And that not knowing is painful. Information gap Theory explains why we keep reading. The Scarcity Principle explains why Caples made us do it.
I’m Getting Three Emails Right Now Just From Copywriters Sharing This.
Each of these headline tricks is a gateway into human psychology. They’re buttons to press, instincts to leverage, hardwired mental habits to exploit. Learning how to write headlines that tap into one or more of them doesn’t make you a designer of minds. It makes you a scam artist. Here are the four tricks.
How curiosity gaps became clickbait.
Information gap theory is the big kahuna, but there are three others. Good headlines pull on at least one of four neural triggers.
Curiosity gaps: the reader knows that they don’t know something, and reading will teach them what’s missing. Any headline that starts with “here’s what nobody tells you about X” is pulling on this trigger.
Self-interest: the reader is instantly able to apply the circumstances, problems, or goals described in the headline to their own life. How to Pay Off Debt In Six Months On A Minimum Wage Salary appeals to the reader who works minimum wage and has debt. The more specific you can make the headline to the reader’s life, the harder it will pull them in.
Specificity: Detailed numbers, names, logos, and qualifiers signal that you know what you’re talking about. Increase Your Conversion Rate By 40% promises more than Improve Your Conversion Rate does because those who read it know that 40% is specific enough to be true — and to be tested.
Social proof (or inversely, surprise): If your headline calls out something readers believe about the world or themselves, or flips an expectation on its head, you’re using this device. The Marketing Strategy That Doubled Our Sales – By Posting Less tugs on social proof because it runs counter to what the reader believes about marketing.
Caples used all four hooks in his masterpiece. It gave the reader a curiosity gap (“but when I started to play?”), an appeal to self-interest (the fantasy we’ve all had of proving the doubters wrong), a dash of irreducible specificity (“they laughed”, “piano”), and finally, brilliant situational irony that flipped the reader’s expectation (“when I started to play”). Every Beautiful headline ticks at least two of these boxes.
Headline Brain Exercise: Break the Rules.
Ideally, you write your headline last. Writing copy is easier if you’ve already decided how you want your readers to feel when they reach the end. But until you know the best headline, you can’t know what mood to leave them in.
So write ten headlines before you write any copy. Really lean into them. The worst headline you write today is better than Pitchbot’s best.
When you’ve got ten options (or whatever number works for you) push select on your favorites. And then ask yourself:
Does it open a curiosity gap?
Does it appeal to my readers’ self-interest?
Did I include a surprising statistic or piece of information?
The headline that does two or more of these things in fifteen words or less is the one you’re looking for.
