An examined document · read the margins
Zero-Sum Thinking
The tendency to assume that one party's gains must come at another party's expense, even in situations where mutual or unlimited gains are possible.
Zero-sum thinking is the belief that gains for one individual or group tend to come at the cost of others. Anthropologist George Foster introduced the related concept of 'image of limited good' in 1965 based on fieldwork in Mexican peasant communities. Daniel Meegan (2010) formally introduced 'zero-sum bias' as a psychological concept, showing that students predicted more low grades after many high grades had been awarded in a non-competitive grading system. Davidai and Ongis (2019) demonstrated that both liberals and conservatives engage in zero-sum thinking when it benefits their ideological positions. Chinoy, Nunn, Sequeira, and Stantcheva (2026) conducted a large-scale survey (N = 20,400) showing that zero-sum thinking predicts support for redistribution, affirmative action, and immigration restrictions, and can be traced back to ancestral experiences.
Zero-sum thinking likely evolved as a cognitive adaptation to ancestral environments where resources (food, mates, territory) were genuinely limited and intra-group competition was intense. In such environments, assuming that another's gain meant one's own loss was often ecologically rational. In modern economies with expandable resources and cooperative institutions, this heuristic misfires, leading people to perceive competition where mutual gains are possible. Davidai and Ongis (2019) showed it is also strategically deployed: people engage in zero-sum framing when it serves their ideological interests.
An alternative account emphasizes cultural transmission: zero-sum beliefs are passed across generations through family narratives and community norms, shaped by historical experiences of scarcity (Chinoy et al., 2026). This suggests zero-sum thinking is not purely an evolved heuristic but also a culturally transmitted worldview responsive to material conditions.
Further annotations
Zero-sum thinking and US political differences. Zero-sum thinking strongly predicted support for government redistribution, race- and gender-based affirmative action, and restrictive immigration policies—effects robust to controlling for partisanship, income, education, and other core beliefs. Zero-sum thinking traced to ancestral experiences: intergenerational mobility (reduced it), immigrant ancestry (reduced it), and exposure to enslavement (increased it).
Sahil Chinoy, Nathan Nunn, Sandra Sequeira & Stefanie Stantcheva, 2026 · not reported
case · 2016 US Presidential Election: Zero-sum rhetoric and cross-party voting (2016)
Chinoy et al. (2026) found that 13% of Trump voters had previously voted for Obama, and zero-sum thinking was a strong predictor of Democrats voting for Trump. Trump's zero-sum rhetoric (immigrants vs. natives, China vs. US) appealed to individuals with zero-sum worldviews across the political spectrum.
case · Trade protectionism and zero-sum beliefs about international trade (2026)
Zero-sum thinking predicts opposition to free trade: individuals who believe that one country's trade gain implies another's loss support protectionist policies. This belief has been documented as a driver of anti-globalization sentiment across multiple countries, despite economists' consensus that trade can be mutually beneficial.
case · Immigration policy attitudes and zero-sum perceptions (2019)
Davidai and Ongis (2019) found that conservatives who viewed the status quo as challenged exhibited zero-sum thinking about immigration—believing immigrants' economic gains come at natives' expense. Chinoy et al. (2026) confirmed that zero-sum thinking predicts anti-immigration preferences across party lines, including among Democrats.
Catch it in the act
When you assume a colleague's promotion means fewer opportunities for you; when trade policies are framed as 'winning' or 'losing' rather than mutual gain; when immigration is viewed as economically harmful to natives despite evidence of overall economic growth; when any gain by one group is automatically perceived as another group's loss.
Cross-references in the margin
- Fixed pie biassiblingFixed pie bias is the belief that in negotiation, the total resources are fixed, preventing integrative ('win-win') solutions. It is a specific application of zero-sum thinking to bargaining contexts.
- Scarcity mindsetparentZero-sum thinking may be seen as a cognitive manifestation of a scarcity mindset—the belief that resources are limited and must be competed for, which can impair judgment and increase tunnel vision on competitive strategies.
- Moral licensingmechanistically-linkedBoth involve social comparison and resource allocation reasoning; moral licensing uses past good behavior to justify subsequent actions, while zero-sum thinking frames all outcomes as competitive.