Robert Cialdini, the 4 million-selling author of "The Psychology of Persuasion"
The world of social psychology guided by world-renowned scholars Douglas Kenrick and Steven Newberg.
Uncovering the secrets of human relationships that govern our thoughts, emotions, and actions.

Human behavior is a mystery in itself.
There are grandmothers who collect waste paper and donate all their wealth, and there are also people who make sacrifices to save strangers.
A person who was once meticulous in everything becomes obsessed with a strange religion, and a person who trembles at the sight of a bug commits a brutal murder.
How should we interpret this behavior, which is difficult to understand simply based on a person's personality or temperament?

World-renowned psychologists Robert Cialdini, Douglas Kenrick, and Steven Newberg answer nearly every question and curiosity about humans and the societies they create in their new book, Social Psychology.
Social psychology is the scientific study of how a person's thoughts, feelings, and behavior are influenced by others.
From self-image management to relationship building, persuasion, agreement and obedience, altruistic behavior, discrimination and violence, and group living, the topics covered in each chapter are all directly related to our real lives.

As a result of the combined efforts of leading figures in social psychology with a combined research experience of 130 years, this book covers everything from classic research you may have heard of to the latest trends in academia.
Solomon Ashi's Conformity Experiment, which revealed that an individual's thoughts and actions can be completely reversed by the thoughts and actions of those around them; Philip Zimbardo's Aggression Experiment, which proved that humans can become unimaginably cruel when given power; and Stanley Milgram's Obedience Experiment, which revealed that humans can become infinitely ruthless in the face of authority, have all provided opportunities for us to reflect on humans as social beings.


Since its original publication in 2014, this book has been used as a textbook, introductory text, and reference book at universities in the United States and Europe.
Professor Kim Kyung-il of the Department of Psychology at Ajou University praised this book, saying, “I can’t count how many times I underlined and read it.” It is a rare work of theory that combines both popular interest and academic perfection.
If philosophy has been asking the question, "What is a human being?" for the past 3,000 years, social psychology, the "king of psychology," offers the most promising answers to that question.
This book, a culmination of over a century of social psychology research, will offer readers a "classic of our time," offering brilliant insights into humanity and society and clues to a better world.

Social psychology can be said to be a consistent and fascinating chronicle.
Of course, the form is colorful and very complex, but if you look closely, you will find that it contains recurring characters, scenes, and themes related to each element.
By providing a framework for an integrated approach to the field of social psychology, this book offers readers the intellectual pleasure of discovering order in chaos and the insight to read society.
--- p.10~11, 「Preface.
From "The Greatest Story on Earth About Humans and Society"

We often underestimate the power of the situation because we assume that the other person's behavior matches their temperament.
Social psychologists call the tendency to attribute behavior solely to temperament the fundamental attribution error.
(……) The impact of a situation on an action is often ‘invisible’ to the observer.
For example, let's say you see your new roommate yelling at your father.
If you didn't know that your friend's father had been unfairly picking on her boyfriend, it would be easy to blame her for her behavior on her spoiled personality.
--- p.128, from “Is it because of personality, whether you do well or not?: The fundamental attribution error”

Lottery winning numbers are chosen randomly, so any combination has an equally slim chance of winning.
But when you pick numbers on a computer, the outcome of a hugely important case with a stake of $1.1 million is safely out of your control.
What do we do then? Just as we roll the dice at a gambling table or wear a lucky T-shirt before an important game, we create the perception of control by choosing the winning lottery numbers ourselves, believing we are in control of the events and circumstances surrounding us.
(……)

Because self-control is so important, people who are deprived of it show distinct reactions.
For example, if you receive a material reward for doing something you like, you may lose interest in that activity.
Because the reward is seen as an attempt to control oneself.
The same goes for school-age children.
Most children will enjoy being rewarded for their learning, but it turns out that such rewards actually discourage children from independent learning.

--- p.142~143, from “Self-Improvement Strategies”

There is a saying that goes, “Flattery is useless.”
But the reality is different.
When done well, compliments can be an effective technique for gaining favor with others.
Another successful form of flattery is to subtly tell your boss through a coworker how much you respect him or her.
If you hear it through a third party, your boss is less likely to feel that the compliment is a tactic.
Asking for advice often works because it shows that you respect the person's expertise and knowledge.
Flattery as a technique of ingratiation begins in preschool age and is often quite successful.
We tend to readily accept compliments we receive while quickly interpreting the flattery of others as empty words.
Why wouldn't they? After all, I'm sure everyone deserves praise when it comes to their own work.
--- p.180, from “How to Make People Like Me”

In the fall of 1973, Robert Cialdini and colleagues discovered that American football fans wore more clothing with their team's logo after a victory.
Fans used the word "we" more when their team won ("We won!") than when their team lost ("They lost!").
By basking in the reflected glory of the winning team, that is, associating themselves with the team known as the winner, fans strengthen their public image.
Conversely, people sometimes exhibit cutting off reflected failure.
This is an act of distancing oneself from known 'losers' for fear of tarnishing one's reputation.
For example, residents of Flanders, Belgium, expressed their political preferences by pasting posters on the front windows of their houses.
After the election, 60% of residents who supported the winning party left their posters in place, while only 19% of residents who supported the losing party left their posters in place.
In this way, networking, which involves associating oneself with winners and distancing oneself from losers, also becomes a means of self-presentation.

--- p.205, from “4 Ways to Demonstrate Influence”

Think of a celebrity you've always liked.
Let's say that person takes a politically opposite stance to you.
According to Fritz Heider's balance theory, having a different opinion from someone you like disrupts the balance of your cognitive system.
How can we relax and restore our cognitive systems to a state of balance? The first way is to change our feelings about celebrities.
Then you will be having a different opinion from someone you don't like.
The second way is to change your attitude toward the subject.
Then you will have the same opinion as the person you like.
(……)

Typically, people change their perspectives to maintain a harmonious connection between the communicator (the subject of persuasion), themselves, and the subject.
This is why advertisers pay huge amounts of money to celebrities or sponsor positive events.
For example, it is said that when a store displays a Visa card sign with an Olympic symbol, the frequency of Visa card purchases increases by 15 to 25 percent.
Tsingtao Beer also reported that its profits jumped 32% during the Olympic period after sponsoring the Beijing Olympics.
--- p.250, from “Why do we want to empower people we like: Balance theory”

Let's recall Solomon Ashi's sympathy experiment.
Participants chose the wrong answer in a line-matching experiment even though they knew it was wrong simply because all their group members had chosen it.
In a situation like this where everyone's opinions are perfectly aligned, people will trust the group's choices more than their own.
(……) But what if someone breaks the consensus by choosing the expected answer before the answer is chosen? In that case, the likelihood of majority agreement becomes much lower.
Because diverse perspectives have the power to suppress consensus, almost all cults suppress communication with external sources of information, including family and friends.
Margaret Singer, who devoted her life to studying cults, would ask victims why they persevered despite the abuse they must have endured within the group.
The most common answers are:
“I look around and think,
'Well, there's still some Joe.
Mary is still holding on.
I was wrong.
“I just don’t understand,” he said.
--- p.288~289, from “Agreement and Similarity”

Car salespeople often "throw the ball low."
They offer certain models at lower prices to entice buyers to choose a specific car.
Then, they escalate their involvement by having the buyer drive the car to their house and spend the night there, or by having them prepare the purchase price, and then, before the final contract is signed, they make all sorts of excuses to make it impossible to sign the contract at that price.
However, by this point, most buyers have experienced a strong psychological involvement with the car, so they often pay a premium to purchase it.
Once people actively choose something, they view it more positively and are less likely to give up.
Once you 'mentally own' an important object, it becomes part of your self-concept.
So, the behavior of car buyers who fall for low-ball tactics makes sense psychologically, even if it makes no economic sense.

--- p.310, from “Personal Intervention and Four Obedience Strategies”

We are drawn to our neighbors partly because the cost of interaction is lower, but also because they are simply more familiar.
At first, the Tibetans regarded Heinrich Harrer as a strange-looking foreigner, but after he had spent seven years in Tibet, they considered him a close friend.
This tendency to think positively about people, places, and things that we see frequently is called the mere exposure effect.
The link between familiarity and preference is so powerful that it also works in reverse.
When you like someone, you become more familiar with that person.
One study found that people not only like people with the same initials as their own (Douglas Kenrick likes Dave Kenney), but also like cities whose names sound similar to theirs (a person named Louis is more likely to live in St. Louis), and even like occupations that sound similar to theirs (a person named Dennis is more likely to be a dentist).

--- p.354, from “When the eyes are close, the heart also becomes close”

In Israel's collective farms, kibbutzim, several children born to different families are raised in groups.
As adults, they remained friends with the opposite sex who grew up in the same group, but they did not marry each other.
This result is contrary to common sense, which states that people tend to marry the person they see often.
First of all, why was this so, when there was no norm within the kibbutz that prohibited sexual attraction?
Joseph Schaeffer attributed this to the interaction of the characteristics of the kibbutz environment and the internal systems that prevented siblings from being sexually attracted to each other.
Mating between siblings, which is more likely to express recessive genes, was a challenge that had to be solved during the evolutionary process.
A typical way to prevent this is for people who grow up under the same roof to develop an aversion to each other's sexual relations.
(……) These findings suggest that it is wrong to ask whether sexual behavior is an evolved genetic system, a sociocultural norm, or a learned experience.
Rather, it is more productive to ask how biological influences interact with culture to influence learning and how that process affects thinking and motivation.
--- p.379~380, from “Why Siblings Don’t See Each Other as the Opposite Sex: A Kibbutz Study”

Governments and citizens of countries that receive foreign aid often respond with resentment and hostility rather than gratitude toward the countries that provided the aid.
How should we interpret the tendency to criticize the actions and intentions of helpers, thereby risking future failures? The answer to this question is complex, but a phrase from French anthropologist Marcel Mauss explains much of it.
“Charity hurts the recipient.”

Research by social psychologists Jeffrey Fisher, Eri Nadler, and Bella DePaulo has clarified the nature and mechanisms of 'wounds'.
Among the self-concepts, the area that gets hurt is self-esteem.
In the process of solving the problem at hand, in some cases, the help itself can threaten self-esteem.
Because being helped can mean that the person is incompetent, inadequate, or dependent.
In such situations, we may refuse or downplay the value of help needed to maintain a positive self-concept.
--- p.442~443, from 「BOX 9.3 “Charity Hurts the Recipient” - Refusal of Help」

Not all aggressive kids are cold-blooded little psychopaths.
In fact, they are afraid of being attacked.
These young attackers generally have two characteristics.
One is being overly emotional, and the other is a tendency to believe that others are threatening them.
Kenneth Dodge and his colleagues developed a social information processing model of child aggression, as shown in Table 10.3, based on their research on aggression in school playgrounds.
--- p.496~497, from “The Self-Defense Man”

There are several reasons why cooperation among members of different groups is effective in reducing hostility.
Cooperation not only provides a means of obtaining economic and social resources in place of competition, but also reduces the tendency for competing groups to view each other in a simplistic way and motivates them to understand outgroup members more accurately.
When you collaborate with people from different groups, you may be less likely to assume that the group only contains similar people, and thus less likely to impose stereotypes and prejudices on others.
Also, we tend to put them in the category of 'us' and consider them as part of it.
As a result, when we cooperate, we develop the mindset that “we are all in this together” and begin to see other groups as we see ourselves, breaking down intergroup prejudices and stereotypes.

--- p.561~562, from “The Power of Contact”

When considering what abilities a leader needs, there are tasks that are more effective with leadership tendencies that are predominantly male, and tasks that are more effective with leadership tendencies that are predominantly female.
However, women may be seen as having a slightly greater advantage in becoming effective leaders because they tend to exhibit transformational leadership more.
The key here is that the most effective leaders, regardless of gender, are those who can adapt their strategies to the environment.
In short, just as leadership emerges, leadership effectiveness is determined by the interaction between people (potential leaders) and situations (groups).
--- p.612~613, from “Conditions for Demonstrating Competence”

In the 1980s, Soviet leader Mikhail Gorbachev used a strategy very similar to GRIT to bring US President Ronald Reagan to the negotiating table.
Gorbachev first offered to suspend nuclear weapons testing in the Soviet Union, then said he would resume it if the United States did not do the same.
His first outstretched hand swayed public opinion in the United States, and Gorbachev extended his hand again the following year, offering to have American investigators verify Soviet arms reductions.
That's how the nuclear arms reduction treaty between the two countries was concluded.
Gorbachev's policy of mutual concessions, which led to a truly fortunate conclusion, is remembered as the key to the end of the Cold War.

--- p.656~657, from 「BOX 13.2 GRIT Strategy that Led to the End of the Cold War」

One science writer recently argued that scientists will soon run out of questions to answer.
This author clearly doesn't know much about social psychology.
The frontier of social psychology is a vast continent, and so far researchers have only sketched the jagged edges of its coastline.
(……) The move to integrate the science of mind and social behavior is not simply a matter of philosophical concern.
There is also significant real potential here.
Social psychology has begun to offer insights into how people can be happier in their social relationships and what factors promote heroism, kindness, and love.
At the same time, by scientifically understanding the forces that motivate negative social behaviors such as aggression, prejudice, and narcissistic selfishness, we provide the key to solving some of the world's most pressing problems today.

--- p.696~697, from “The Future of Social Psychology”