Zero-Sum Thinking
The assumption that any situation is a competition where one person's gain must be another's loss.
Also known as: zero-sum bias, fixed-pie bias
What it means
Zero-sum thinking is the automatic assumption that resources, status, or success come in a fixed quantity - so if someone else gets more, you must be getting less. It treats life like a card game: every chip that moves to your opponent’s side of the table came from yours.
In a genuine zero-sum situation - a tennis match, a single job vacancy, a literal poker game - this is accurate. One person wins, the other loses. But most real-world situations aren’t like this. Trade creates wealth that didn’t exist before. Education benefits everyone in a society, not just the person who received it. A neighbour’s success doesn’t diminish your own. Yet our brains frequently default to the competitive frame, because for most of human evolutionary history, resources really were scarce and fixed - the fruit someone else picked was fruit you couldn’t eat.
The bias becomes dangerous when it shapes how we think about groups. Research by Sara Solnick and David Hemenway at Harvard found that roughly half of people, when given the choice, would prefer to earn £50,000 in a world where everyone else earns £25,000 - rather than earn £100,000 in a world where everyone else earns £200,000. They’d accept half the real purchasing power just to be ahead. The pie doesn’t matter; what matters is your slice relative to everyone else’s.
In the real world
Immigration debates are almost always framed in zero-sum terms: “they’re taking our jobs,” “they’re using our services,” “there isn’t enough to go around.” The framing assumes a fixed number of jobs and a fixed pot of public money. In practice, immigrants also create jobs, pay taxes, and expand the economy - but that’s a harder story to tell than “your slice is shrinking.”
In workplaces, zero-sum thinking drives the belief that a colleague’s promotion threatens your own prospects, even when the team is growing. In relationships, it shows up as scorekeeping - “I did more than you” - rather than recognising that mutual investment grows the relationship for both people.
Perhaps the sharpest demonstration comes from behavioural economics experiments. When participants are given the choice between both players receiving £5 each, or receiving £3 themselves while the other person gets just £1, a significant number choose the second option. They’d rather have less in absolute terms as long as the gap is in their favour. That’s zero-sum thinking in its purest form: it’s not about the money, it’s about the hierarchy.
How to spot it
When someone frames a situation as 'us versus them' - where helping one group automatically hurts another - ask whether the pie is really fixed. In most real-world situations, it isn't. Trade, cooperation, and creative solutions can grow the total. If the argument only works by assuming there's a fixed amount to go around, zero-sum thinking is doing the heavy lifting.
The thought to hold onto
Most of life is not a poker game. The instinct to treat every situation as a competition is one of the deepest barriers to cooperation - and one of the easiest levers for anyone who wants to turn people against each other.
Why it matters now
Zero-sum thinking is the silent engine behind much of today's most divisive political rhetoric. Immigration debates, welfare policy, culture wars - all are frequently framed as though one group's gain must come at another's expense. Once you see the frame, you see it everywhere.