• David de Souza

Influence Summary: The Psychology of Persuasion

Updated: Jul 20


The most useful takeaway from this book is one that can save yours or someones else's life: Pluralistic ignorance. The tendency to look to see what others are doing and to use that inaction as a cue. If you (or someone else) ever need emergency help, do not allow bystanders to come to their own conclusions. Isolate one person, stare, shout and point at them and no one else: "You sir, in the black jacket, I need help I am having a seizure, call an ambulance".

Want to dig deeper than the core principles? Check out:


Core Principles:


I have summarised 'Influence', distilling the book into 27 core principles:

  1. We have created a world so complex and with so much information that we must deal with it using shortcuts like animals that we once transcended.

  2. Fixed action patterns are blindly mechanical behaviors in species. For example: A robin will attack a clump of red feathers but leave a stuffed replica without the red feathers. Humans also have these triggers.

  3. Stereotypes are necessary. We can not analyze all information. We do not have the energy, time or capacity.

  4. "Civilization advances by extending the number of operations we can perform without thinking about them" - Alfred North Whitehead

  5. When making decisions we often rely on shortcuts when we are: (ITURDS) Indifferent Tired Uncertain Rushed Distracted Stressed

  6. Reciprocity is so strong that even if the person is disliked it will still work.

  7. We are more likely to become influenced when we are asked for a big request, which is followed up with a smaller request, even if we are interested in neither. For example Boy Scouts selling circus tickets and countering with a chocolate bar.

  8. Rejection then Retreat Technique: Make a large ask, something you know you'll be rejected for, and then ask for the item that you wanted initially. The optimal strategy is: exaggerate the initial position enough but not too much.

  9. You can enhance your likability with: Attractiveness - Grooming well. Similarities - Age, religion, politics, interests, Complement - Tell people you like them Contact - Familiarity usually results in greater liking Working together - Use 'we'

  10. "Since 95% of people are imitators and 5% initiators, people are persuaded more by the actions of others than by any proof that we can offer".

  11. In the same way that a recorded "cheep-cheep" sound can cause a bird to be mothering, even when there is no chick present. Television executives exploit the same shortcut by using canned laughter to stimulate us to laugh.

  12. Pluralistic ignorance is the tendency to look to see what everyone else is doing and to use that inaction as a cue. In a staged experiment, 85% of people helped an epileptic having a seizure when they were the only person present but this decreased to 31% with 5 bystanders present.

  13. When you need emergency help, do not allow bystanders to come to their own conclusions. Isolate one person, stare, shout and point at them and no one else: "You sir, in the black jacket, I need help I am having a seizure, call an ambulance".

  14. A society built on authority provides many advantages, including the development of resource production, trade, defense, expansion and social control. Guidance from a recognized authority provides a useful shortcut, helping us to decide how to act.

  15. A well-tailored suit can result in deference from strangers: 3.5 x more people followed a person wearing a suit who walked into traffic at a crossing.

  16. People who write down a statement are more committed to it even after new evidence is provided, especially those who do so publicly. People who do not write down a statement are more willing to change their minds.

  17. The greater the effort and pain involved in a commitment, the greater the influence on the person. For example, initiation ceremonies.

  18. Consistency is powerful in influencing human behavior because of 'commitment'. Researchers asked people to predict if they would vote on election day. As most people want to seem virtuous they said 'yes' and this acted as a commitment device and more people went to vote.

  19. Charities use consistency when calling and asking "How are you?" Our natural reaction is to say "Fine/Good" and they then reply with "I'm glad to hear that because I am calling to see if you can help the unfortunate victims of...."

  20. Foot-in-the-Door Technique: Start by asking for a small request in order to gain compliance for a larger request.

  21. Throwing a Low-Ball Technique: The seller does not intend to sell at the low price, their only goal is to get the buyer to decide to buy. Once this is done a number of steps cement the commitment: Paperwork, financing, etc.

  22. People are more motivated by loss than by a proportional gain.

  23. We want an item when it is scarce and we want it, even more, when we are in competition for it.

  24. When customers were told of forthcoming scarcity due to exclusive information (vs non-exclusive) they purchased 6 times more.

  25. When information is banned we have a greater need for that information and our perception towards that information is more favorable and believable.

  26. "We are most likely to find revolutions where a period of improving economic and social conditions is followed by a short sharp reversal in those conditions. It is not traditionally the most downtrodden people - who have come to see their deprivation as part of the natural order of things- who are especially liable to revolt. Instead, revolutionaries are more likely to be those who have been given at least some taste of a better life. When the economic and social improvements they have experienced and come to expect suddenly become less available, they desire them more than ever and often rise up violently to secure them.

  27. The 6 factors to influence someone are: (SCARS L) Social Proof Commitment and Consistency Authority Reciprocation Scarcity Liking


Let me know how these summaries can be improved? Contact me via Email (david@thisdomain.co) or on Twitter.



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