An American research team has confirmed the social balance theory, which states that a friend of a friend is a friend, and an enemy of an enemy is a friend.
- Social balance theory explains that human beings innately try to find harmony in their social circles.
- Social bonds would therefore be dominated by four main rules: the enemy of an enemy is a friend, the friend of a friend is a friend, the friend of an enemy is an enemy and the enemy of a friend is an enemy.
- American researchers managed to confirm this theory using statistical physics.
The enemy of my enemy is my friend. We’ve all heard this famous proverb, but is it really true? Developed by Austrian psychologist Fritz Heider, the theory of social balance, which implies this famous phrase, indicates that human beings strive to find harmony in their social circles. According to the specialist, our social links are governed by four rules: the enemy of an enemy is a friend, the friend of a friend is a friend, the friend of an enemy is an enemy, and the enemy of a friend is an enemy. These principles would lead to balanced relationships.
A theory confirmed by statistical physics
Until recently, no study had confirmed this theory. Researchers from Northwestern University (United States) were therefore interested in this hypothesis. “We always thought that this social intuition worked, but we did not know why (…) If we consult the literature, we see that there are many studies on this principle, but that there are no no agreement between them. For decades we continued to get it wrong. The reason is that real life is complicated. We realized that we had to take into account two constraints simultaneously: who knows who and that some people are simply friendlier than others.”said István Kovács, lead author of the study and assistant professor of physics and astronomy in the Weinberg College of Arts and Sciences at Northwestern University.
To test Heider’s rules, people are characterized by nodes. The edges connecting the nodes represent the relationships between individuals. A negative, or hostile, value is assigned to the edge when two nodes are not friends, while the edge is rated with a positive, or friendly, value when the two nodes are friends. In previous research, positive or negative values were assigned randomly without taking into account the two constraints previously cited by István Kovács.
Friendly people are more likely to have positive interactions
In their work published in the journal Science Advances, the scientists studied four publicly available network datasets previously processed by social scientists. The data came from:
- user-reviewed comments on the social news site Slashdot;
- exchanges between members of Congress in the House of Representatives;
- interactions between Bitcoin traders;
- of product evaluations on the consumer review site Epinions.
Within this network model, researchers did not assign truly random negative or positive values to edges. In order for each interaction to be truly random, each node would need to have a proportional chance of meeting each other. In real life, we do not necessarily know all the people who make up a social network. For example, we don’t know all of our friends’ friends.
The authors of the study therefore distributed them on the basis of a statistical model, which describes the probability of distributing positive or negative signs to existing interactions. The values are thus random, but they are within the limits given by the constraints of the network topology. They also took into account that some people are friendlier than others, and are therefore more likely to have more positive interactions.
With the addition of these two constraints, this model indicated that large-scale social bonds are consistent with Fritz Heider’s social balance theory. “We now know that we must take these two constraints into account (…) Without them, it is impossible to find the right mechanisms. It sounds complicated, but it’s actually pretty simple math.”said István Kovács.
