In human and animal collectives, perceptions and evaluations of physical strength are often used to resolve conflicts before actually engaging in combat. Picture the gorilla furiously pounding his chest, a wild goose spreading and beating its vast wings, or two humans “squaring up” and bumping chests. Often these displays serve to avoid actual physical contest, which is riskier for both parties.
Social psychologists have hypothesized that humans, and specifically male humans, may make similar evaluations even when strength is not a relevant factor to the conflict. This is largely based on the fact that humans are quite adept at judging upper-body strength; that children use size and strength cues to predict conflict outcomes; and that physical strength correlates with self-reported measures of conflict success.
To test whether humans use strength cues to regulate their behavior in conflicts unrelated to physical strength, researchers from Aarhus University in Denmark pitted participants against each other in a war-of-attrition game with or without visual cues of their opponent’s strength (an anonymous silhouette of their body shape).
In the war-of-attrition game, each of the 375 male participants started with 225 units of game currency. With each second of gametime, a unit of currency was lost. The longer a participant stays, the more they lose. However, the participant to last the longest without withdrawing received a prize of 100 units. Participants only learn whether they’ve won or lost after withdrawing.
For example, if Player A withdraws after 60 seconds and Player B after 70 seconds, Player A will leave with (225 – 60) 165 units, while Player B leaves with (225 -70 + 100) 225 units.
While the results of the study showed a positive correlation between an opponent’s strength and their perceived disposition to aggression, no significant correlation was found between perceived formidability of one’s opponent and actual game behavior. The authors take this as evidence against the hypothesis that human males use strength cues to resolve conflict where strength is irrelevant to the outcome.
There are many caveats however, as noted by the authors, including the fact that real-world conflicts come in a variety of forms, while a number of social factors, like physical presence and cues of aggression like facial expression, likely also come into play.
Understanding how humans regulate their behavior in conflict settings has far-reaching implications, from the social to the political and financial. Stock markets, voting and political science, military behavior and other domains all encompass aspects of conflict and a wide variety of non-combat resolutions.
The study, “Do physically stronger males prevail in non-physical conflicts?” appeared in Evolution and Human Behavior in January, 2021.
