The Rule of 3.

I was a strategy consultant at McKinsey for a little over a year and a half, and learned an incredible amount during that time that has helped me as an entrepreneur. McKinsey offered a lot of formal training on problem-solving, leadership and communication. After all, as McKinsey consultants, we often needed to persuade C-level execs of large companies to make decisions that would change their company and sometimes even their industry. But it was often the “pro-tips” – the informal learning shared between team members on a project – that stuck with me.

Here’s one pro-tip that I learned from one of my mentors at McKinsey: The Rule of 3. Whenever you’re trying to persuade a senior person to do something, always present 3 reasons. Not 2, not 4, but exactly 3.

If I was asked by a senior exec, “Why should we do this?”, I was advised to respond with, “There are 3 reasons why we should do this” and then proceed to list my reasons in almost a numbered bullet point format (“First…”, “Second…”, and “Last…”).

I observed that The Rule of 3 was actually pretty effective in persuading clients to take action. Why? Three reasons:

1. Your argument gets their attention and is memorable

2. You are forced to choose the 3 most important reasons

3. You sound more structured, confident and decisive when you speak

Your argument gets their attention and is memorable

When you present 3 reasons, they tend to be absorbed and remembered. When you start your response with a phrase like, “I’ve got three reasons why we should do this,” it gets people’s attention because most of us have been hard-wired to expect things in groups of 3. It started with childhood, when we heard fairy tales about things in groups of 3 (“3 little pigs”, “Goldilocks and the 3 bears”, etc.). Since then, we have become conditioned to hear concepts in groups of 3 (“blood, sweat, and tears” or “government of the people, by the people, and for the people” or “mind, body, spirit”), so it’s a pattern that we are receptive towards. Furthermore, research on human psychology has found that our working memory is best capable of remembering at most 3 or 4 chunks of information.

Busy senior executives are no exception to this rule. They are often inundated with information, and with requests for decisions. Breaking down your argument into 3 reasons gets their attention, allows them to quickly process and later remember the key soundbytes from your argument.

You are forced to choose the 3 most important reasons

If your audience is only going to remember 3 reasons anyway, present them with the 3 most important reasons. If you want to be thorough and exhaustive, you may come up with a huge number of reasons (like 5 or 10) to support your argument. Rather than actually presenting all of the reasons, focus on the 3 most important that will be the most effective with your audience. If you are really having trouble prioritizing, and you think that reasons 4 and 5 are must-haves, you can also group all of the reasons into 3 categories. But in a world where senior execs are being flooded with information, prioritizing to only your top 3 reasons will focus their attention on your most powerful arguments.

You sound more structured, confident and decisive when you speak

When you start your response with, “I’ve got 3 reasons why we should do this,” and then you list out the reasons in bullet points, you sound like you know what you’re talking about. Your response comes across as backed by structured reasoning, which makes your argument more credible. Delivering your response in bullet point format also forces you to be direct and crisp, which has the added benefit of making you sound more confident. You aren’t perceived as waffling, unsure, or confusing—you are perceived as decisive, certain, and clear. This in turn inspires confidence from the senior execs who are listening to your recommendation.

One of my colleagues at McKinsey thought that the Rule of 3 was so effective, he would occasionally start a response with, “I’ve got 3 reasons why we should do this” without even having thought of the 3 reasons ahead of time. His mind would be racing furiously to come up with reasons 2 and 3 while he was explaining reason #1. The most important reason— the one that he had originally come up with—would be first. The 2nd and 3rd reasons would usually still be effective, but even if not, the overall power of his argument went up because he used the Rule of 3.

The Rule of 3 is a helpful McKinsey pro-tip that makes your argument to busy senior executives more memorable and persuasive. It shouldn’t be overused, otherwise it could be perceived as gimmicky. But I have seen multiple examples of how, if used judiciously at the right time, the Rule of 3 helped us to change senior executives’ minds and motivate difficult decisions. This is a good skill for everyone—but especially for entrepreneurs—to have to become more effective, persuasive leaders.