Our Gemara on Amud Beis discusses social group dynamics.  If a coin fell from one of three people, the finder is not obligated to return it. What is the reason? The person from whom the coin fell certainly despairs of recovering it. He says, “After all, two other people were with me. If I seize this one, he will say: I did not take it. And if I seize that one, he will say: I did not take it.” Since he cannot make a definitive claim, he despairs of recovering his coin.

 

The sages were aware of the social dynamics that affect decision making and moral calculus, often affecting Halacha. Here are a number of other examples from the Talmud:

 

For example, the Gemara (Eiruvin 3a) discusses a high beam which requires a constant vigilance to remain halachically valid (for certain reasons explained over there), and makes a distinction between its status for a private Succah versus a public Eiruv. Even though it is technically Kosher, in regard to the private Succah, there is a high degree of confidence that he will continue to maintain it. However, regarding the public Eiruv, since no one individual has responsibility for it, there is a fear that its maintenance will be neglected. The Gemara quotes the following aphorism:

 

A pot belonging to partners is neither hot nor cold. 

 

That is to say, when responsibility falls upon more than one person, each relies on the other, and ultimately the task is not completed.

 

Similarly, The Gemara (Sotah 8a) discusses the way in which a sinner might be wrongfully encouraged by like-minded peers:

 

Two Sotah women are not given to drink simultaneously, in order that the heart of each one not be emboldened by the other, as there is a concern that when one sees that the other woman is not confessing, she will maintain her innocence even if she is guilty. 

 

Social psychology research calls this phenomenon ‘Diffusion of Responsibility’.  This is when the presence of others changes the behavior of the individual by making them feel less responsible for the consequences of their actions. 

 

Researchers Beyer, Sidarus, Bonicalzi, and  Haggard (Journal of Social Cognitive Affective Neuroscience. 2017 Jan; 12(1):138–145. “Beyond self-serving bias: diffusion of responsibility reduces sense of agency and outcome monitoring”) report that Diffusion of Responsibility leads to decreased helping and increased aggression in group behavior. 

 

The researchers devised a clever experiment whereby they used a task in which a marble rolls down a bar, and an action is required to stop it from crashing. Participants either played alone or allegedly together with another player. If the participant acted, the marble stopped immediately, so they could unambiguously attribute the outcome to their own action. As the diffusion of responsibility concept is mostly used to explain behavior in situations where acting is somehow costly or effortful, or results in negative consequences, the researchers designed the task to exclusively produce negative outcomes. Stopping the marble incurred some cost for the participant, but this cost was avoided if the other player stopped the marble.  The researchers used EEG readings to measure and correlate similarity and differences between responses that indicated a sense of personal responsibility versus deflection of responsibility. 

 

Their findings were that the presence of another potential agent (person who could stop the marble) reduced participants’ sense of agency over those outcomes, even though it was always obvious who caused each outcome. Further, presence of another agent reduced the amplitude of feedback-related negativity evoked by outcome stimuli, suggesting reduced outcome monitoring. 

 

Of course, this has important implications on how mobs, or even like-minded, political groups can justify inhumane behavior, and on a personal level how we may rationalize our own misdeeds.  We only need to read the so-called news to see how this plays out in the social and political realm.