When you contemplate the reasons for people forming hard and fast distinctions between themselves and others, those reasons may seem to be anything but logical. We are all people. So why do groups of people, sometimes based on only minor differences, line up so readily against themselves, sometimes at their peril?
It’s well known in sports that people form strong allegiances to their own team, whether based on geography (hometown), family traditions, or even team mascot or color. Ardent fans of these teams literally despise the fans of the opponents. This is a classic example of ingroup-outgroup bias, the tendency to favor people who share some quality with you while you dislike or even loathe people who share the opposite quality.
Life outside the sports arena not only replicates this effect but also can turn it into massive societal ills, ranging from border wars to the hoarding of resources during times of need. Political polarization between left and right is on the rise, causing rifts not only in government but also in families and potential romantic partners. A recent question on Instagram posed readers with the dilemma of whether they would date a person from the opposite political persuasion. What would your answer be?
The Ingroup-Outgroup Bias and Prosocial Behavior
It probably goes without saying that the bias people feel toward their ingroup would translate into behaviors intended to help (the ingroup) or hurt (the outgroup). According to new research by Max Planck Institute (Bonn)’s Rima-Maria Rahal and Vienna University of Economics and Business’ Frederik Schulze Spüntrup (2025), “the activation of in-group bias… [can have] tragic consequences.” Such tragedies include struggles around the distribution of vaccines and medical equipment during the COVID-19 pandemic, taking responsibility for the climate crisis, and the rise of xenophobia, in which nations try to protect their borders to fight off foreigners.
What’s particularly puzzling is that ingroup favoritism can be based on purely arbitrary distinctions, such as, in one set of prior studies, the preference for one artist vs. another, or even groups formed by random flips of a coin. You can create an ingroup out of almost anything. Once set, future decisions by ingroup members continue to be made without regard for either the arbitrariness or, as in the case of nations, the fact that all people are members of the same ingroup (i.e., people).
According to Rahal and Spüntrup, ingroup favoritism, once established, becomes a cognitive bias that can, as it continues, be fanned by cultural factors. Maybe some cultures are better able to foster cooperation than others, overriding whatever internal barriers people form in their own ability to play nicely with opponents.
An International Test of Ingroup Favoritism
The Rahal and Spüntrup study used the “dictator game,” in which participants decide how much to award another player to either maximize their own benefit or share cooperatively with that other player. Teams were arbitrarily formed by having participants choose a color (e.g., “Team Blue”). If the ingroup bias is operating, players would play cooperatively with their own teammates, but try to maximize their selfish rewards with outgroup members. Although players get more of the pot if they choose selfishly, the pot is bigger if they make cooperative choices.
All of the findings, sadly, pointed to the universality of the ingroup bias. People just did not want to make decisions that would benefit people who differed from them, even on this arbitrary basis. As the authors concluded, “behavioral in-group favoritism is prevalent across the globe.”
Maybe the kernel of good news you can glean from this dismaying observation is that people were not just plain out for themselves alone. They did make decisions that could benefit an ingroup member. What isn’t so great is that participants from cultures that foster individualism vs. collectivism showed even higher rates of ingroup favoritism: “individualistic cultures provide fertile ground for in-group biases because of the increased need and craving for identification with different possible in-groups,” observed the authors.
But, but, but, you ask yourself, are we inevitably fated to hate those we see as different from ourselves? Here’s another tiny piece of good news. By adding one small manipulation to the method, the authors identified “colorblind” participants who preferred not to know who they were competing against before the game started (45 percent of the sample). These individuals seemed to go out of their way to avoid showing favoritism to their ingroup when it came to deciding how to allocate resources in the game.
The final piece of the puzzle was the question of what cognitive processes go into making decisions about whether to benefit friend or foe. By using webcams, the researchers could see how much effort participants put into their decisions. It appeared that ingroup favoritism involved more cognitive processing, especially in some countries vs. others.
Can Ingroup Bias Be Overcome?
If biases instilled in the lab by a simple experimental task can produce solid ingroup favoritism, there must be something fundamental that all of this taps into. Indeed, the authors cite what’s called the “Material Security Hypothesis” to explain why people tend to hoard resources with their own kind when those resources are scarce. Remember the early days of COVID-19 when you couldn’t find paper towels or toilet paper? People weren’t terribly inclined to offer these precious commodities to anyone other than family (if that).
The implication is that in a world with unlimited resources, everyone would happily share with everyone else, including groups they despise. However, resources are limited. So what can you, as an individual, do to contribute to a less biased world?
To address this question, Yale University’s Danni Yang and colleagues (2025) suggest the value of “framing intergroup cooperation” not as “zero-sum competition” but as “contexts of mutual benefit” or problems that everyone faces. Shortages can be opportunities to set group differences aside while everyone looks for a common solution.
To sum up, finding ways to overcome differences, whether arbitrary or more culturally ingrained, can help all find paths to fulfillment.
