The Zero-Sum Bias: When People Think that Everything is a Competition

Zero-Sum Bias


The zero-sum bias occurs when people mistakenly expect gains and losses to be directly balanced in a situation where they’re not, especially in terms of one party benefiting directly at the expense of others. For example, the zero-sum bias can cause someone to think that a resource they’re interested in is limited, meaning that to use it they will have to take some of it from others, even if the resource is actually unlimited.

The zero-sum bias and specific forms of it are sometimes referred to using other names, including zero-sum heuristic, zero-sum intuition, zero-sum fallacy, zero-sum thinking, zero-sum mentalityzero-sum mindset, zero-sum beliefsbelief in a zero-sum game, fixed-pie bias, fixed-pie perception, and win–win denial.

The zero-sum bias can influence people’s thinking and behavior in various situations, so it’s important to understand it. As such, in the following article you will learn more about the zero-sum bias, understand its causes, and see what you can do to reduce its influence.


Examples of the zero-sum bias

An example of the zero-sum bias is someone assuming that in a trade between two people, one must be directly benefitting at the expense of the other, even though both people might benefit equally and not at the expense of one another, since each of them places a different value on what they’re giving and receiving.

Another example of the zero-sum bias is a child mistakenly believing that their parents’ love toward them must come at the expense of their parents’ love toward the child’s siblings (and vice versa), even if this isn’t the case, unlike with some other parental resources, such as time and attention.

The zero-sum bias could also cause someone to mistakenly view their and their colleagues’ credibility and competence as being zero-sum, meaning that to make themselves look better they have to bring others down. Similarly, in a political context, this bias could cause someone to mistakenly assume that the legitimacy of certain individuals, groups, or institutions must come directly at the expense of others, even when that’s not the case.

Furthermore, the zero-sum bias can affect interpersonal relationships in various other ways, including on a societal scale. For example:

  • People sometimes incorrectly view membership in certain social groups as being zero-sum, meaning that belonging to one social group excludes you from being a member of a different group.
  • People sometimes incorrectly view certain gender dynamics in the workplace as being zero-sum, which can cause them to be more opposed to gender-fair policies.
  • People sometimes incorrectly believe that there’s inherent zero-sum competition between ethnic groups, which can cause them to develop negative attitudes toward immigrants.
  • People sometimes incorrectly view discrimination (e.g., racism or sexism) as a zero-sum game, meaning that they believe that a decrease in discrimination against one group will be balanced by increased discrimination against other groups.

Similar issues can apply to divisions based on other grounds, such as political ideologies, religious beliefs, and nationalistic attitudes, and can influence perspectives toward other things, such as workplace relations, help giving, and economic success.

In addition, the zero-sum bias is sometimes actively encouraged by certain parties for their benefit. For example, some politicians try to increase the public’s support of them by making the public believe that certain resources are more limited and zero-sum than they are. This often involves the lump of labor fallacy, which in this context represents the idea that there’s a fixed amount of labor to be distributed within the economy, so the entry of new people into the job market must come directly at the direct expense of others.

Finally, the zero-sum bias can also play a role outside social contexts. For example, this can be the case when consumers assume that if a product is superior in one regard, then it must be inferior in other regards, because they think that its good qualities must be balanced by bad ones (e.g., if they know that a phone is durable, then they might expect it to have poor performance). Similarly, this bias can also influence the way people make career decisions, for instance when they assume that if a certain job pays more then it must have a worse work-life balance. Additionally, this bias can also influence people’s thinking when it comes to many other things, such as evaluating evidence and searching for information.


Dangers of the zero-sum bias

The zero-sum bias can lead to various issues, including:

  • Increased interpersonal conflicts and decreased cooperation, especially when this bias promotes belief in an antagonistic nature of social relationships, and makes people mistakenly believe that mutual gain is impossible. Furthermore, the bias can sometimes lead to escalation, for example one party displays a zero-sum bias, which causes the other party to react in a negative way and display the bias too, out of retaliation and because they assume that the first party knows something that they don’t.
  • Increased immoral behavior, for example this bias drives people to justify acting in a selfish or discriminatory way.
  • Worse ability to assess information and make decisions in many everyday situations, for example when choosing what products to buy or what career path to follow.

These issues play a role on both individual and group scales. For example, the zero-sum bias could cause an individual to achieve worse outcomes due to their misguided unwillingness to cooperate with others, or it could do the same for government institutions.


Psychology and causes of the zero-sum bias

There are several cognitive mechanisms that can lead to the zero-sum bias:

  • Scarcity beliefs. This involves thinking that certain resources are more limited than is actually the case. This, in turn, can lead to related beliefs, such as that there won’t be enough of those resources for everyone, so people must compete for them.
  • Belief in tradeoff consistency. This involves thinking that the various advantages and disadvantages of available options in a choice set must be balanced (a form of compensatory inference). This can lead people to discount the advantages of superior options, since they assume these advantages must be balanced by some disadvantages, or to ignore the disadvantages of inferior options, since they assume these disadvantages must be balanced by some advantages.
  • Difficulty in understanding other people’s different perspectives. For example, this can involve a failure to understand that two people involved in an exchange might view it as being beneficial for different reasons.

These mechanisms, in turn, can be caused by various underlying mechanisms. For example, difficulty in understanding other people’s perspectives reflects an issue with theory of mind, and can be caused by the egocentric bias. Similarly, beliefs in tradeoff consistency can be caused by previous experience with commonly associated tradeoffs, which are then assumed to occur even in situations where they aren’t. Likewise, scarcity beliefs can also be caused by previous experiences, for example when people assume that a resource is scarce now because they had to compete for it in the past.

Many of these mechanisms serve as heuristics, for example when people need to make a decision quickly on the basis of limited information, so they rely on their past experience to assess a present situation, even if this increases their risk of reaching a wrong conclusion. Accordingly, the zero-sum bias has been proposed to potentially be an evolutionary adaptation, since for the majority of human history, most resources were highly limited, and so this sort of thinking may have encouraged people to compete for them when it was beneficial to do so.

A combination of these mechanisms may underlie the zero-sum bias. Furthermore, other mechanisms may also cause this bias, such as intuitive mercantilism (the belief that people’s welfare is determined by monetary wealth rather than their command of useful goods and services), and entitlement beliefs (e.g., feeling entitled to all of a certain resource, even if its quantity isn’t fixed and some of it could go to others without a cost to oneself).

Finally, it’s important to keep in mind that there are situations that are indeed zero-sum, meaning that any gains by one party are directly balanced by the losses of other parties. However, the issue with the zero-sum bias is that it causes people to believe that situations are zero-sum, when that’s not actually the case (e.g., when a change can be mutually beneficial to all the parties involved, meaning that the gains of each party don’t necessitate a loss by other parties).

Note: The zero-sum bias is a psychological phenomenon, while the concept of zero-sum games comes from economics and game theory. Because of the prevalence of this bias, it’s considered to be a notable feature of folk economics, which is the intuitive view of economics that’s held by people who lack formal knowledge on the topic. It’s associated with other concepts in psychology, such as crab mentality.


Asymmetric bias

An asymmetric zero-sum bias is the mistaken belief that other people’s gains must come directly at one’s expense, but not vice versa. For example, a person who displays an asymmetric bias could assume that any promotions that their colleagues receive must come directly at this person’s expense, but that promotions that this person receives don’t come directly at their colleagues’ expense.

Conversely, in a symmetric zero-sum bias, gains are seen as coming directly at someone else’s expense, regardless of who’s gaining and who’s losing.


Social competition

From a social perspective, the zero-sum bias often involves mistaken belief regarding either intra-group competition for a certain resource (between a person and other members of their social group), or inter-group competition (between a person’s ingroup and various outgroups).


How to avoid the zero-sum bias

Because of the potential issues that the zero-sum bias can cause, it can be beneficial to understand how to avoid displaying it yourself. Furthermore, it can also be useful to understand how to avoid causing it in others (e.g., to minimize backlash against policies you propose), and how to reduce it in others when it isn’t caused by you (e.g., if a family member displays it due to a politician’s manipulation).

The following are key techniques that you can use to do this, which you can choose from and modify depending on factors such as your goals and situational constraints:

  • Increase general awareness of this bias. For example, this can involve explaining what this bias is, illustrating its potential influence using relevant examples, and explaining what can cause it.
  • Identify specific instances of the bias. For example, this can involve identifying specific areas of your life where you’re likely to encounter this bias, or identifying past situations where you likely displayed it.
  • Address the situation with explicit reasoning. For example, this can involve explaining to someone what resources are involved in a certain situation, why they might think that the situation is zero-sum, and why it’s not zero-sum in reality.
  • Consider and address specific causes of the bias. For example, if you think that the zero-sum bias is caused in a certain situation by mistaken scarcity beliefs, you can show that the resource in question isn’t actually scarce. Similarly, if you think that the bias is caused due to a difficulty in understanding someone else’s perspective you can try to visualize that person’s perspective, to consider that they might have different motivations and preferences than yours.
  • Use general debiasing techniques. For example, you can slow down your reasoning process, to give yourself more time to think critically about a situation, and improve your decision-making environment, to make it easier to think without the presence of relevant manipulators or peer pressure.

It can also be beneficial to understand the zero-sum bias even if you don’t try to reduce it, since it can help you better understand and predict people’s behavior, including your own. For example, understanding this bias could help you understand why some people are irrationally opposed to a certain public policy that they incorrectly think will come at their expense, or to predict that a certain politician will encourage such irrational thinking to increase public support.


Summary and conclusions

  • The zero-sum bias occurs when people mistakenly expect gains and losses to be directly balanced in a situation where they’re not, especially in terms of one party benefiting directly at the expense of others.
  • For example, the zero-sum bias can cause someone to think that a resource they’re interested in is limited, meaning that to use it they will have to take some of it from others, even if the resource is actually unlimited.
  • This bias can lead to issues such as increased conflict, decreased cooperation, and worse assessment of information.
  • This bias can be caused by various mechanisms, such as thinking that some resource is more limited than it actually is, believing that positive traits must be directly balanced by negative ones, and struggling to understand that different people may value things differently.
  • To reduce the zero-sum, you can increase awareness of this bias, identify specific instances of it, address the situation with explicit reasoning (e.g., to show that it’s not actually zero-sum), address specific causes of this bias (e.g., by visualizing other people’s perspectives), and use general debiasing techniques (e.g., slowing down your reasoning process).