My mom tells a story from long ago when I was very young — barely 3 or 4 years old. My grandfather asked me what I hoped to learn at preschool.

“Three things,” I replied. “How to read, how to play the piano, and how not to cry when I have a shampoo.”

I share this story not just to point out my long-ago comedic timing, but because it’s my own personal proof that we’re hard-wired to be receptive to the single, simplest, most powerful rule of communication.

That rule is called the Rule of 3, and it underpins some of the most effective speeches, jokes, and stories that we all know. A few examples:

• During times of peril, we talk about dedicating “blood, sweat, and tears” to the cause, about a nation “of the people, by the people, for the people,” and values including “life, liberty, and the pursuit of happiness.”
• When we’re children, we read stories about the Three Little Pigs, Goldilocks and the Three Bears, and maybe even the Three Musketeers.
• Or else, we tell jokes when we get older: “A doctor, a lawyer, and an engineer are playing golf one beautiful morning…” (I’ll finish the joke at the end of this article.)

More relevant and instructive for you now, as a business leader, is to examine how we use the Rule of 3 habitually, how we actually seek it out when we’re listening to others, and yet, paradoxically, how people often forget the rule when it could help the most.

The Rule of 3 works for at least three reasons (no surprise there, I’m sure):

• First, because human beings respond to patterns, and the optimal number of things that are required to create a pattern is three. Fewer than three, and there’s no pattern; more than three, and the chances of overthinking and finding false or irrelevant patterns increases.
• Second, because we respond to change, and if you articulate three things, you almost always create an imbalance that leads to change. The odds are that either all three things go together, or that two of them go together, while the third represents an exception. It’s either 3 to 0, or else 2 to 1; either rhetorical outcome changes the status quo ante.
• Finally, because most people can remember three things at the same time without taking time to study them. The U.S. Marine Corps uses the Rule of 3 throughout its organization for exactly this reason: three Marines in a fire team; three fire teams in a squad, etc.

In fact, it was the Marine Corps angle, which I first read about in Inc. magazine back in 1998, that initially drew me to articulate this concept, or at least to identify it more readily. (When the Marines experimented with a Rule of 4, author David H. Freedman wrote, effectiveness plummeted.)

So, how should you use the Rule of 3 in business if you’re not already? A few examples:

• Optimally, meetings, presentations, and plans should be organized around three big objectives or agenda items. This doesn’t always mean ignoring other items; it can mean reorganizing them so that they reflect groups of three.
• When leading or counselling employees: Identify two things that the employee is doing well and one key thing to improve. This often might mean meeting more often but about fewer things, for example.
• In advertising and marketing: Focus on three benefits to the customer. Bonus points, at least sometimes, if the third of the three can be a bit incongruous or apposite; that’s where the humour can come from.

Speaking of which:

A doctor, a lawyer, and an engineer are playing golf one beautiful morning. The group ahead is moving slowly, and they’re annoyed until they learn that it’s a foursome made up of firefighters who lost their sight while rescuing people from a burning building.

• “They’re heroes,” says the doctor. “I wonder if any of my physician friends can help.”
• “I agree,” says the lawyer. “I’d love to offer my services to help them get compensated.”
• “It’s too bad,” says the engineer. “But why can’t they just play at night?”