Social Diffusion

Responsibility diffuses among animal groups, influencing behaviors related to safety and morality.

For schools of fish, herds of antelope, and human societies, a felt need for safety motivates group cooperation. Surrounded by peers, individuals lower their vigilance and calmly go about their business.

Body language provides a social cue of safety. There are 3 universal responses to sensing danger: flight, fight, or freeze. “Freezing is a safe way of conveying the existence of danger to others,” explains Portuguese biologist Marta Moita. “This does not require a signal that may result in drawing unwelcome attention. Also, freezing may constitute a public cue that can be used by any surrounding animal regardless of species.”

The more of a herd there is, the more assuredly animals feel about others providing a proper social context. For instance, fruit flies react to perceived dangers individualistically until there are 6 in a group. Then they relax into a feeling of safety as a communal undertaking.

Diffused responsibility also applies to acceptable behaviors. Moral laxity and conformist tendencies come to the fore in human groups. A herd mentality takes hold.

French social psychologists Gabriel Tarde & Gustave Le Bon wrote of a hive mind behind mob behavior in the late 19th century. But crowd psychology has been understood – and used by rabble-rousers – for millennia.

Humans are indistinct from fruit flies when it comes to diffusion of responsibility. A most notorious incident of such occurred on 13 March 1964, when 28-year-old Kitty Genovese¬†was raped and repeatedly stabbed to death in the middle of the street in a residential neighborhood in Queens, New York City: a brutal murder that took nearly a half-hour. 38 people witnessed the killing. None attempted to intervene. Not even one lifted a telephone to call the police. “The responsibility for helping was diffused among the observers; there was also diffusion of any potential blame for not taking action,” remarked American social psychologists John Darley & Bib Latan√©.

The brutality and atrocity that are so common in human conflicts are a group dynamic, abetted by camaraderie amid mortal stress. Such as been recently seen in protests by Americans for police accountability which only resulted in more brutality and murder by police.

As a group endeavor, human morality is a sinking to a lowest common denominator – and that denominator is practically primal. As Irish politician Edmund Burke observed in the 18th century, “The only thing necessary for evil to triumph is for good men to do nothing.” From all appearances, the good men in the world are assiduously doing nothing.


Ishi Nobu, “Diffusion of responsibility,” in The Echoes of the Mind (2019).

Scientists discover a social cue of safety,” (21 August 2020).

Clara H. Ferreira & Marta A. Moita, “Behavioral and neuronal underpinnings of safety in numbers in fruit flies,” Nature Communications (21 August 2020).

Ken Eisold, “Understanding why people riot,” Psychology Today (18 August 2011).