“I feel in competition with certain people and I think that any gain for them inevitably entails a loss for me.”
Sometimes we feel in competition with other people or other social groups , which can lead us to develop a cognitive bias: the zero-sum bias. The principle of zero-sum implies that in a competitive situation, one person's gains are directly counterbalanced by the other person’s losses. Indeed, considering social relations as a competition can make us believe that any advance for a person or a social group, whether in terms of rights, resources, or status, will necessarily be accompanied by an equivalent loss for us or our social group . However, in most cases, this competition does not exist, and the gains of other people are not conditional on equivalent losses for us. This biased perception of relations between groups has serious social consequences, as it generates negative or even hostile attitudes towards people or social groups perceived as competitors. Several studies suggest that men and groups with high social status are more likely to have zero-sum beliefs than women  and groups with lower social status [2, 3].
Relations between women and men are fertile ground for the emergence of zero-sum beliefs. Indeed, studies show that men are more likely to see themselves in competition with women than the reverse , which leads men to think that any progress for women (in terms of rights, status, etc.) becomes a loss for them. This is suggested by a study , which showed that, over the past six decades, men have observed a decrease in discrimination against women and that at the same time, they believe that discrimination against men has increased. This zero-sum belief constitutes a bias because, in fact, discrimination against men was not shown to have increased during this period. During this same period, women observed the same decrease in discrimination against their gender, but did not observe an increase in discrimination against men. Perceiving women as competitors makes men believe that gains made by women represent losses for them.
The principle of zero-sum, derived from game theory, describes competitive situations in which the gains of one person are counterbalanced by the losses of another. This is the case with most gambling games, such as poker, in which the sum won by the winner is the total of the bets lost by the other players. This concept, applied to psychology, makes it possible to explain certain relations and certain conflicts between social groups.
According to the Instrumental Model of Group Conflict , zero-sum beliefs emerge when one social group perceives itself to be in competition with another. This perceived competition appears when a group or an individual covets a resource considered to be limited because it is rare or unevenly distributed and another competing group or individual appears. These beliefs lead to negative or even hostile attitudes and behaviors towards the competing group, with the objective of eliminating the competition.
In our example, women are perceived by men as a competing group capable of monopolizing scarce or unequally distributed resources such as civil rights. Men therefore perceive themselves in competition with them and develop the zero-sum belief that if women obtain new rights, it means that men lose them. This belief is a bias because in truth, women and men are not in competition in terms of rights and giving rights to women in no way implies taking them away from men. These beliefs translate into negative attitudes (for example, prejudice) or even hostile behavior (for example, discrimination, aggression) of men towards women.
The zero-sum bias has great consequences for relations between social groups, since it causes the group or individual who perceives themselves to be in competition to adopt an anxious and defensive attitude towards the competing individual or group. This encourages the emergence of negative attitudes, stereotypes, and racist and sexist prejudices. Zero-sum beliefs create a vicious circle that promotes the emergence of stereotypes from which destructive self-fulfilling prophecies will flow. This is the case of gender prejudices which are at the origin of self-fulfilling prophecies such as the glass ceiling, which refers to all the invisible obstacles that prevent women from progressing socially and professionally as quickly and as much as men. These negative attitudes can also lead to discriminatory behavior (rights, hiring) or even hostility (verbal and physical aggression) towards the competing group. The zero-sum bias is therefore a real driver of conflict between social groups.
Thoughts on how to act in light of this bias
Here are some questions to ask yourself to avoid falling into the trap of zero-sum beliefs:
Is this resource really rare? Am I really competing for this resource?
Is the resource scarce or unequally distributed? Does my competitor have a less legitimate claim to this resource than I?
Is my strategy to eliminate the competition fair to my competitor?
How is this bias measured?
The majority of studies focusing on zero-sum biases are conducted using questionnaires that aim to measure the dispositions of one social group or individual towards another. The theoretical framework developed by the researchers links the perceived competition between various social groups, such as men and women  or natives and immigrants  and the zero-sum beliefs and negative attitudes of these various groups . It is in this way that a cause-and-effect link has been demonstrated between these three factors: perceived competition favors the emergence of a zero-sum bias which in turn favors the emergence of negative attitudes towards the competing group.
This bias is discussed in the scientific literature:
This bias has social or individual repercussions:
This bias is empirically demonstrated:
 Esses, Victoria M., Dovidio, John F., Jackson, Lynne M., & Armstrong, Tamara L. (2001). The immigration dilemma: The role of perceived group competition, ethnic prejudice, and national identity. Journal of Social issues, 57(3), 389-412.
 Wilkins, Clara L., Wellman, Joseph D., Babbitt, Laura G., Toosi, Negin R., & Schad, Katherine D. (2015). You can win but I can't lose: Bias against high-status groups increases their zero-sum beliefs about discrimination. Journal of Experimental Social Psychology, 57, 1-14.
 Ruthig, Joelle C., Kehn, Andre, Gamblin, Bradlee W., Vanderzanden, Karen, & Jones, Kelly (2017). When women’s gains equal men’s losses: Predicting a zero-sum perspective of gender status. Sex Roles, 76(1), 17-26.
 Kehn, Andre, & Ruthig, Joelle C. (2013). Perceptions of gender discrimination across six decades: The moderating roles of gender and age. Sex roles, 69(5), 289-296.
 Esses, Victoria M., Jackson, Lynne M., & Armstrong, Tamara L. (1998). Intergroup competition and attitudes toward immigrants and immigration: An instrumental model of group conflict. Journal of social issues, 54(4), 699-724.
Intergroup level, Interpersonal level, Need for security, Need for social belonging
Audric Mazzietti, Doctor of psychology, instructor and researcher at the ESDES, Université Catholique de Lyon. Bibliography available on: https://www.headtech.fr. This entry was translated from French to English by Susan D. Renaud.
How to cite this entry
Mazzietti, A. (2022). Zero-sum bias, trans. S. D. Renaud. In G. Béghin, E. Gagnon-St-Pierre, C. Gratton, & E. Muszynski (Eds). Shortcuts : A handy guide to cognitive biases Vol. 5. Online: www.shortcogs.com