The 6 Principles of Persuasion

The 6 Principles of Persuasion

“Persuasion is often more effective than force.”
— Aesop

Learning how to influence others is an enormously beneficial skill.

It allows you to get what you want with the least amount of effort.

You can use it at home or work, and the more you practice it, the easier it becomes to achieve your goals.

So how can you become more persuasive?

The best place to learn about this powerful art form is from the work of Dr Robert Cialdini.

Dr Cialdini has spent his career researching the dynamics of persuasion and published his first book, Influence: The Psychology of Persuasion, back in 1984.

To research his psychology classic, he spent three years ‘undercover’ training at used car dealerships, fundraising organisations and telemarketing companies to witness real-life examples of persuasion.

In all, he identified six ways you can influence others.

The reverse is also true, so awareness of these principles can help you avoid someone using them on you.

Let’s take a closer look at how each technique works below:

1. Reciprocity

You are inclined to do things for people who have helped you in the past.

Apart from mean-spirited psychopaths, there is an inbuilt desire in all human beings to return a favour.

This behaviour comes from when we roamed the African plains, and resources were scarce. 

If someone gave you leftover food when you were starving, you were only too happy to do the same for them when the roles were reversed.

In one famous experiment, a researcher sent Christmas cards to almost six hundred strangers.

Included in each card were a picture of his family and a note.

You might expect someone who did this to get just a handful of replies, but he received nearly two hundred responses.

So how is this principle used to influence you?

One technique retailers employ is to offer you a free drink as you browse their store.

Because you feel they’ve done something kind for you, you are more likely to buy something from them in response.

Waiters use a similar strategy to increase their tips. When they present the bill, it is accompanied by a small gift such as chocolates.

The lesson here is that if you want someone to do something for you, do something for them first.


2. Consistency/Commitment

You like to be consistent with your past behaviour.

Everyone likes to behave in a way that is consistent with things they have previously said or done.

This means that if you behaved one way in the past, you are more likely to commit the same behaviour again in the future.

It’s why you stick to current ways of thinking even when new information arises and why old habits die hard.

It’s also why salespeople try to get you to agree to a small request upfront, as it increases the chance you will agree to something bigger later on.

This sneaky technique is called the ‘foot-in-the-door’ effect.

So how can you use this desire to behave consistently to your advantage?

One way is to use a ‘commitment device’.

A commitment device is a way to persuade yourself to do something good you might otherwise not have done.

For example, you will run more frequently if you join a running club than rely on self-motivation.


3. Social proof

The behaviour of others influences your own behaviour.

If you see or believe people to behave in a certain way, you are more likely to adopt the same behaviour.

This herd mentality is an evolutionary hangover from when doing what others were doing, like running away from danger would have saved your life.

In other words, we assume that if many people are doing something, they must know something we don’t.

What’s a good example of this?

Let’s take the humble shopping trolley.

When Sylvan Goldman invented a device with wheels to make shopping easier, nobody would use them.

But when Goldman paid actors to use his new invention in his stores, suddenly, everyone else started using one.

Another example of social proof in action is signage in public parks that say, ‘Most people take their litter home with them’.

Social proof is also why brands talk about being the most popular in their category, and positive reviews persuade us that a company’s product is trustworthy.


4. Liking

You are more likely to be persuaded by someone you like.

The more we like someone, the more likely we will buy from or help that person.

One way to get another person to like you is by pointing out a shared commonality, such as the same hobby or place of birth. 

This makes the other person feel more rapport with you. 

This phenomenon explains why the best salespeople ‘mirror’ their prospects. 

It’s also why compliments from someone endears us to them. They must be sincere, though!

The reverse is also true.

As Dr Cialdini writes in his book, “There is a natural human tendency to dislike a person who brings us unpleasant information, even when that person did not cause the bad news. The simple association with it is enough to stimulate our dislike.”


5. Authority

You are more likely to believe somebody if they are in a position of perceived authority.

If a doctor or policeman asks you to do something, you’re more likely to do it than if asked by a random stranger.

This phenomenon explains why adverts for toothpaste often feature dentists. Or why criminal gangs often use fake uniforms to gain entry into buildings.

Oh, and don’t forget the famous experiment by Stanley Milgram, which used actors in lab coats to persuade participants to administer increasingly large doses of electric shocks to strangers in another room.

If you’re suspicious of somebody’s authority on a topic, it’s good to ask yourself, ‘Is there a reason this person is recommending this product other than its merits?’ 

Online influencers, we’re looking at you.


6. Scarcity

You value things more if they are in limited supply.

As a species, we have spent most of our history in a world of scarcity, not abundance.

There were no supermarkets on the African savannah, so if we came across something of value, we would gather it up immediately as we couldn't be sure when we would come across it again.

How do companies use this to their advantage?

One trick is to use limited-time offers or feature limited edition products. The belief that the supply might run out soon motivates us to purchase.

In an A/B test study of 6,000 e-commerce sites, ‘scarcity’ was the most powerful conversion tactic.

7. Unity

You are more likely to do something for someone with a shared identity.

We said six principles, but we meant seven. 

The sneaky Dr Cialdini added a final one to his original list.

He calls this principle ‘unity’, and it explains why we are happy to do things for other members of our ‘tribe’.

Family is the most obvious one. 

In one experiment with university students, Dr Cialdini wanted to see the difference between students' and their parents' response rates for filling out a questionnaire.

Typically, parental response rates were low (often below 20%) compared to a high completion rate for students. 

How did Cialdini close the gap? 

He offered the students an extra point on a test if their parents filled out the survey.

The parents couldn’t help but comply, knowing they were helping their treasured offspring.


If you found the above post helpful, be sure to check out our Behavioural Economics course, which explores these and other techniques in more detail.

42 Laws You Should Know (Part 1)

42 Laws You Should Know (Part 1)

3 Key Learnings from FT Climate Capital

3 Key Learnings from FT Climate Capital