How gossip became humanity's oldest viral trend

By Hugo Francisco de SouzaFeb 25 2024Reviewed by Susha Cheriyedath, M.Sc.

In a recent study published in the journal Proceedings of the National Academy of Sciences, researchers devised an evolutionary game-theoretic model and a series of agent-based tests to elucidate the evolution and persistence of gossip, arguably the most ubiquitous social human trait. Their study evaluates their hypothesis that reputation dissemination and selfishness deterrence form the keystone features of gossip’s evolutionary stability and subsequently tests the causal pathways of this evolutionary cycle.

Their findings suggest that information dissemination regarding an absent third party can prompt individuals to condition their own behavior in response to others’ reputations. When paired with the tendency of individuals to behave cooperatively towards gossipers to better their own reputations, gossiping has and will continue to remain prevalent in human society for the foreseeable future.

Explaining the evolution of gossip. Image Credit: Ollyy / Shutterstock

Gossip – the world’s best-shared mystery?

Gossip is the social dissemination of (often unconfirmed) information regarding an absent third party, usually conducted in an informal or unconstrained conversation. History reveals that gossip has been a fundamental trait of human civilization since ancient times, the earliest records of which may be found in Mesopotamia and ancient Greece. Science hypothesizes that gossip may be a common trait amongst hunter-gatherer societies, with equivalents detected in higher primate groups.

Research estimates that people today spend approximately one hour each day partaking in gossip. Surprisingly, studies have failed to elucidate significant inter-cohort differences in gossip’s ubiquity, with all individuals, irrespective of age, sex, societal standing, and personality types, indulging in the activity. However, just as surprising is that through thousands of years of gossip’s existence, we still do not know where it came from, how it permeated every known human civilization, and how it has remained one of the most prevalent human indulgences to this day.  

“Previous theories tried to explain the origin of gossip in terms of its role in human survival, particularly for bonding large groups and sustaining cooperation. Gossip disseminates information about people’s reputations and, as such, enables people to choose to help cooperative others and avoid being exploited by selfish ones—a mechanism that is widely studied as indirect reciprocity that sustains cooperation. Beyond that, the possibility of being gossiped about also elicits people’s reputational concerns. As a result, people tend to behave more cooperatively under the threat of gossip.”

Despite these hypotheses having their scientific merit, they focus on gossip’s benefits while failing to explain the evolution of gossip in the first place. Gossip is time- and energy-consumptive and involves sharing knowledge, an essential resource in a resource-restricted environment. Gossip should thus be maladaptive and not arise in natural populations, with mutants being quickly removed via natural selection. Furthermore, these hypotheses highlight the benefits to the gossiper while underplaying the role and stochasticity of benefits to the receiver – the information gained from the gossip event must first guide and modify the receiver’s behavior before any material benefits can be gained.

The evolutionary cycle of gossip

The present study proposes ‘the evolutionary cycle of gossip,’ which hypothesizes that the interplay and positive feedback between reputation dissemination and selfishness deterrence allows gossip to establish itself as an evolutionary stable strategy (ESS). Using agent-based computer simulations, they then build a game-theoretical model incorporating two gossiping functions to test this hypothesis. Once established, they further use simulations to test the pathways involved in this escalating causal relationship.

“…we argue that the reputation dissemination function of gossip makes reputations more accessible and, thus, leads more people to take others’ reputations into account when interacting with them. As more people condition their behavior on others’ reputations, more people get concerned about their own reputations, too. This reputational concern drives them to manage their reputations by behaving more cooperatively when interacting with gossipers.”

The model incorporates two decision strategies for each gossip game player – ‘cooperation’ and ‘gossiping.’ This decision tree then dictates the circumstances and degree of cooperation of the players under different scenarios and based on six personality types, including unconditional cooperators (AC), unconditional defectors (AD, players who use reputation information to protect themselves (CC), and players who use reputation information to exploit others (CD). The final two categories are gossiper-sensitive and subject to the selfishness deterrence function of the gossip trait.

The study’s reputation system represents its key innovation and dictates the process of players developing belief systems about their counterparts. Their reputation system design allows players to infer each other’s conditional behavior and avoids additional confounds of higher-order moral judgments.

“With this setup, agents form assumptions of each other’s underlying strategy, instead of evaluating each other simply as “good” or “bad” dichotomously or on a one-dimensional spectrum as in previous models.”

Study findings

Out of the 5,000 simulations run, an overwhelming majority (90%; N = 4,000) presented the evolution of gossip, all of which allowed for prevalence and eventual population-wide establishment of the trait, validating its robustness as an evolutionary strategy. Surprisingly, even when suboptimal or maladaptive, gossip was still established in populations unless its maladaptive costs were scaled too high.

Study findings revealed that the exploitive (GC) strategy was the most adopted (57%) amongst players. Despite this, overall cooperation rates across the population remained high (78%). This is attributed to progressive increases in gossiper densities and population-wide reputation sensitivity. Reputation dissemination function analysis elucidates these results by revealing that gossip results in increased reputation accessibility, allowing players to make more accurate predictions of their neighbors’ strategies.

“…gossipers evolve under a wide range of parameter choices though the proportions of them vary as a function of these parameters. Particularly, more gossipers evolve if individuals are in a social network where they have a lot of stable connections, if they have in-depth interactions with these social connections, if they interact frequently, if they have conversations with each other frequently, if their beliefs are influenced by gossip from moderately to greatly, and if the evolution happens slowly.”

Conclusions

In the present study, researchers develop a novel hypothesis to explain the evolution and persistence of gossip and devise a game-theoretical model and agent-based tests to simulate the hypothesis’ validity. Their findings suggest that gossip evolves from the escalating positive feedback interaction of reputation dissemination and selfishness deterrence. Their simulations highlight the robustness of the trait and its persistence once the trait has emerged within a population.

Similar modeling frameworks applied to other aspects of human interaction may help elucidate the prevalence of behaviors we consider routine but have profound evolutionary and survival implications.