The Psychology of Persuasion: How You Get Manipulated

This article is an excerpt from the Shortform summary of "Influence" by Robert B. Cialdini. Shortform has the world's best summaries of books you should be reading.

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Have you ever noticed how some people are gifted in the psychology of persuasion? Without even realizing what’s going on, you’re convinced to buy, join, or do something. Robert Cialdini’s principles of influence identify the six key parts to the psychology of persuasion.

We’ll cover the basics of Cialdini’s six principles of persuasion and how each one can be used to manipulate us.

The Six Principles of Persuasion

There’s no end to the list of specific persuasion tricks and tactics, but most compliance practitioners play upon (or prey upon) six psychological principles that guide human behavior. These principles of persuasion are:

Reciprocity
Consistency
Social proof
Liking
Authority
Scarcity

All of these six principles of persuasion are fixed-action patterns. When we encounter any of them in the real world, our instincts prime us to respond in particular ways. Compliance practitioners know this better than anyone. And with an effective command of Cialdini’s six principles of influence, they can manipulate us into doing just about anything.

They are able to do this with a light touch. When compliance practitioners do their job right, they convince you that you truly want what they’re offering—and all they’re doing is satisfying that want. The most effective persuasion is that which doesn’t feel like persuasion at all.

Cialdini’s Principle #1: Reciprocity

The psychology of persuasion using the Reciprocity Principle tells us to repay others when they do something for us. Most of the time, it just feels like common decency: when a friend treats you to lunch, you pay for their meal the next time; when your neighbors invite you over, you return the courtesy.

The first of Cialdini’s six principles is an evolutionary inheritance: early human communities with strong social cohesion and an ability to work together had a better chance of survival. By knowing that a favor would be returned, reciprocity helped to lower the “costs” of helping one’s neighbors and kin.

Cialdini’s Principle #2: Commitment/Consistency

The psychology of persuasion using the Consistency Principle says that humans have an obsession with sticking to their guns. Once we’ve committed to something, we pressure ourselves to conform to that commitment. In fact, we’ll convince ourselves that our current behavior and beliefs align with our past behavior and beliefs, even when they clearly don’t.

For example, gamblers who are unsure about their bets before they place them have been shown to be far more confident after they’ve put their money on the table. They convince themselves that they were always confident in the horse they picked or the color on the roulette wheel they chose. This is an example of Cialdini’s principle of commitment at work.

Consistency is generally useful for day-to-day human experience and it’s usually a good attribute for someone to have. It frees us from potential mental overload by giving us an easy, one-size-fits-all guide for how to react to a multitude of situations and people that we encounter each day.

Cialdini’s Principle #3: Social Proof

The psychology of persuasion using the Social Proof Principle posits that we decide what’s correct based on what other people think is correct. If lots of other people are doing something or thinking something, then it must be good and worthy of imitation. It’s why television producers add laugh tracks to unfunny sitcoms: they know that, through social proof, we’ll be more likely to laugh if we hear others laughing (even if we don’t find the content to be funny on its own). This is an example of one of the six principles of persuasion at work.

Of course, social proof is often valuable: you’ll tend to make fewer mistakes if you follow social evidence than if you ignore it. When a lot of people are doing something, it usually is the right thing to do. We can look to others for how to model our behavior in everyday situations, rather than needing to meticulously analyze everything.

Cialdini’s Principle #4: Liking

The psychology of persuasion using the Liking Principle stipulates that we’re more likely to comply with requests from people that we know and like. Thus, we are more amenable to the compliance efforts of neighbors, friends, and family. It’s why salespeople will often mention the names of members of your family or friends that they’ve done business with. The salesperson wants you to translate some of your warm feelings about those individuals onto them. They are applying one of Cialdini’s principles of influence.

We are also more willing to acquiesce to people who we see as being good-looking, affable, or who profess to like us. This creates a wide opening for compliance practitioners. If you like the seller, you’ll like what she’s selling. The efforts at manipulation can be almost comically transparent and still be effective: one car salesman claimed great success just by mailing generic postcards to his customers every month saying nothing more than “I like you.” This is an example of one of Cialdini’s six principles of persuasion in action.

Cialdini’s Principle #5: Authority

The psychology of persuasion using the Authority Principle states that people are hard-wired to comply with requests that come from an acknowledged and accepted source of authority. Thus, we are strongly inclined to be deferential to people whom we consider to be in a position of power or expertise, like teachers, members of the armed forces, police officers, doctors, and judges. In fact, we respond to even just the symbols of authority—like titles and uniforms. This is an example of one of Cialdini’s principles of influence.

Of course, there are good and legitimate reasons why we’re strongly conditioned to obey authority. Leadership, hierarchy, and authority are obviously necessary ingredients in any functioning society. Our ancestors wouldn’t have been able to organize complex societies if there hadn’t been some authority figure giving orders, assigning priorities, and allocating resources. Indeed, authority is the basis of government and law: without it, there’s only anarchy.

Cialdini’s Principle #6: Scarcity

The psychology of persuasion using the Scarcity Principle tells us that we find more appealing those things with limited availability. Thus, rare goods are expensive, abundant items are cheap. Scarcity is closely related to the idea of loss aversion. We’re inherently conservative and cautious: in fact, we’re more afraid of losing something than we are enticed by the hope of gaining something of equal value.

Like our other fixed-action mental shortcuts, scarcity usually is a good gauge of how valuable something is. It’s simple supply-and-demand: when there’s less of something and there’s a high demand for it, the price increases. It’s why gold is more valuable than iron and why high-skilled workers earn more than low-skilled workers. Cialdini’s principles of influence make sense even if they can also be used to manipulate people.

All of Cialdini’s principles of persuasion turn our greatest strengths into some of our greatest vulnerabilities. Compliance practitioners are adept at fooling us by activating our fixed-action patterns to get us to agree to whatever it is they’re trying to push on us. Thus, they’ll give you “free” samples; manipulate you into making seemingly innocuous commitments; create phony social proof, butter you up with flattery; put on a fake uniform to lend themselves the air of authority; or give you a made-up deadline to make you think your time to act is limited. Knowledge is power: the more you know about Cialdini’s six principles of influence, the better prepared you’ll be to resist them.

The Psychology of Persuasion: How You Get Manipulated