Influence: The Psychology of Persuasion by Robert Cialdini

Reading Time: 3 minutes


A deep dive into what drives people to say “yes.” A great book for people interested in getting more out of life. A few of the key lessons include the tendency to reciprocate favors, the power small commitments, and how what you see or experience first influences how you think about what comes next.

Buy this book on Amazon (Highly recommend)

Access My Searchable Collection of 100+ Book Notes

Key Takeaways

The power of “because”

When you ask someone for something or make a decision about something, always tell them why. As humans, we are more likely to accept an outcome if we understand why that outcome is happening. So whether you need to say no to someone who has asked you to dinner or cut a line at the airport, let the person know why. For example,  “Can I cut the line because I need to catch my flight to get home to my family?”

Contrast principle

The order in which we see or experience something influences how we perceive that thing and the subsequent things we see or experience. For example, if you are giving a strategy presentation with two potential options, show the least desirable option first. When you do this, the second more desirable option will be perceived as even better because it will be contrasted with the less good option.

This principle also applies to the psychology of purchasing items. For instance, after we make a large purchase, such as that of an automobile, we are more likely to purchase the add-on items that we are offered (e.g., enhanced GPS, better stereo) because those purchases will seem small relative to the big purchase of the automobile.

Rule of reciprocation

The rule of reciprocation goes as follows: When someone gives us something, we feel obligated to give them something back. This drive for reciprocity influences our actions in powerful ways.

For example, if your friend buys you a drink, you feel obligated to repay them. You might buy them a drink, pay for a cab home, or invite them for dinner. Often, you will give them something of greater value than what they gave you.

To fully leverage this principle, you can start with a big request from someone, and once they deny, deliver a smaller request. In contrast to the bigger request, the smaller request will seem much more reasonable, and the person is more likely to accept.

Drive for consistency

As humans, we have an immense drive to be consistent. Consistency is perceived as a positive personality trait that is highly valued in our society. That’s why when we tell someone that we will do something or we create an image of ourselves as someone with specific values, we are very likely to do the thing we said and to be consistent with our values even when that means doing something that we don’t particularly enjoy.

If you’re interested in learning more about our drive for consistency, read Mistakes Were Made, But Not by Me, which is a fascinating deep dive into how this drive influences most of our life.

The power of small commitments

In Chinese POW camps, American soldiers were asked a simple question, “Is America perfect?” Despite their extreme loyalty for America, when posed with this question, it was easy to say and write down one small way in which America was not perfect.

The Chinese then escalated this initial request to having prisoners write essays on how America could be improved and then having the prisoners read these essays, which they recorded. When Americans watched these recordings, it looked as if the American soldiers had turned on their country.

What the American public didn’t realize is that this process of asking small things from the prisoners occurred over months, and it was done with small commitments. Over time, the prisoners said things that they never would have said in the beginning.

Without using any violence, the Chinese military used the power of small commitments to get American soldiers to speak out against their own country.

The principle here is simple: small commitments have the power to lead to much larger ones. So if you want someone to do something, start slow and ask for little. Over time, those little requests may compound and lead to the big outcome you’re seeking.

If you want to discover more great books...

If you want the latest book notes in your inbox...