Last Updated on by Vanessa Cast

Time to read: ~7 min

6 principles of persuasion

What happens inside people’s mind?

Do people evaluate all the available information while deciding to say yes or no?

I would say yes, but according to marketing, business and psychology expert Dr. Robert Cialdini, we take shortcuts.

Harvard Business Review lists Robert Cialdini’s research in “Breakthrough Ideas for Today’s Business Agenda.” He is a New York Times, Wall Street Journal, and USA Today Best-Selling author. Fortune Magazine lists Influence in their “75 Smartest Business Books.” CEO Read lists Influence in their “100 Best Business Books of All Time.”

Cialdini, the master of persuasion, identified 6 universal shortcuts that guide our decision-making.

You just need to address these 6 principles in an ethical manner and people will be scientifically proven to be more inclined to say yes to your requests.


Obligation to give when you receive. People are more likely to say yes to those that they owe

One of the best demonstration comes from a series of studies conducted in restaurants. In the study, given diners a single mint at the end of their meal, typically increased tips by around 3%.

If two mints are provided, tips don’t double, they quadruple, a 14% increase in tips.

People are more likely to say yes to those that they owe Click To Tweet

Most interesting is the fact that if the waiter provides one mint, starts to walk away from the table, but pauses, turns back and says, “For you nice people, here’s an extra mint”, tips go through the roof.

A 23% increase influenced not by what was given, but how it was given.

Be the first to give and ensure that what you give is personalized and unexpected.


People want more of those things there are less of. When British Airways announced in 2003 that they would no longer be operating the twice-daily London-New York Concorde flight because it had become uneconomical to run, sales the very next day took off. It becomes a scarce resource.

You need to point out what is unique about your proposition and what they stand to lose if they fail to consider your proposal Click To Tweet

It’s not enough simply to tell people about the benefits they will gain if they choose your products and services, you also need to point out what is unique about your proposition and what they stand to lose if they fail to consider your proposal.


Physiotherapists, for example, are able to persuade more of their patients to comply with recommended exercise programs if they display their medical diplomas on the walls of their consulting rooms. People follow the lead of credible knowledgeable experts.

Persuasion - Authority

It’s important to signal to others what makes you a credible knowledgeable authority before you make your influence attempt.

You can hardly go around telling potential customers how brilliant you are, but you can certainly arrange for someone to do it for you.

And surprisingly the science tells us that it doesn’t seem to matter if the person who introduces you is not only connected to you but also likely to prosper from the introduction themselves.

People follow the lead of credible knowledgeable experts Click To Tweet

Go and find the authorities in your field, provide value to then so you can get their attention and make you worthy of mention.


People like to be consistent with the things they have previously said or done. Consistency is activated by looking for and asking for small initial commitments that can be made.

In one famous study, researchers found rather unsurprisingly, that very few people would be willing to erect an unsightly wooden board on their front lawn to support a Drive Safely campaign in their neighborhood.

However, in a similar neighborhood close by, 4 times as many homeowners indicated that they would be willing to erect this unsightly billboard.

Why? Because ten days previously, they had agreed to place a small postcard in the front window of their home that signaled their support for a Drive Safely campaign.

That small card was the initial commitment that led to a 400% increase in a much bigger but still consistent change.

People like to be consistent with the things they have previously said or done Click To Tweet

Looks for voluntary active and public commitments and ideally gets those commitments in writing.


People prefer to say yes to those that they like. But what causes one person to like another?

Persuasion science tells us that there are 3 important factors:

  • We like people who are similar to us.
  • We like people who pay us compliments.
  • We like people who cooperate with us towards mutual goals.

In a series of negotiation studies carried out between MBA students at two well-known business schools, some groups were told, “Time is money, get straight down to business”.

In this group, around 55% were able to come to an agreement.

We tend to like people who are similar to us, pay us compliments or cooperate with us Click To Tweet

A second group, however, were told, “Before you begin negotiating, exchange some personal information with each other. Identify a similarity you share in common then begin negotiating”.

In this group, 90% of them were able to come to successful and agreeable outcomes that were typically worth 18% more to both parties


Especially when they are uncertain, people will look to the actions and behaviors of others to determine their own.

You may have noticed that hotels often place a small card in bathrooms that attempt to persuade guests to reuse their towels and linen.

Most do this by drawing a guest’s attention to the benefits that reuse can have on environmental protection.

It turns out that this is a pretty effective strategy leading to around 35% compliance, but could there be an even more effective way?

Well, it turns out that about 75% of people who check into a hotel for four nights or longer, will reuse their towels at some point during their stay.

They simply change the information in the cards and said that “75% of our guests reuse their towels at some time during their stay. Please do so as well”.

It turns out that when we do this towel reuse rises by 26%.

Now imagine the next time you stay in a hotel you saw one of these signs. You picked it up and you read the following message: “75% of people who have stayed in this room have reused their towel”. What would you think?

Like most people you’d probably think that the sign will have no influence on your behavior whatsoeve, but it turns out that changing a few words on a sign to honestly point out what comparable previous guests have done was the single most effective message leading to a 33% increase in reuse.

Especially when they are uncertain, people will look to the actions and behaviors of others to determine their own Click To Tweet

If you want to learn more, you must check on these Robert Cialdini’s books, he is the master of persuasion and these books are his masterpiece:

Explains the psychology of why people say “yes” and how to apply these understandings

and the also New York Times + Wall Street Journal Bestseller:

The secret doesn’t lie in the message itself, but in the key moment before that message is delivered

This animated video describes the six universal Principles of Persuasion we talked about earlier. If you can choose only one, what would be? Leave a comment and let me know!

With Love ♥

Vanessa Cast Signature

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