Ever notice how your kids can go from best friends to sworn enemies in the space of ten minutes? Or how one coworker's habits suddenly become the hill everyone else wants to die on? Whether it's siblings, classmates, or workplace teams, conflict is part of life. Sometimes it's small squabbles, other times it feels like an all-out turf war.

But psychology has something useful to say here—and the lessons are surprisingly practical.

The Summer Camp Rivalry That Got Out of Hand

Back in the 1950s, psychologist Muzafer Sherif ran a famous experiment at a summer camp. He split boys into two groups: the Rattlers and the Eagles.

At first, the groups didn't know about each other. They bonded within their own team—coming up with names, flags, even songs. But when the two groups were introduced, Sherif staged competitions. Things got heated fast. We're talking name-calling, flag burning, food fights, even raiding each other's cabins to steal property.

In other words, the kids behaved just like... well, siblings, coworkers, or rival school groups.

Then came the twist: Sherif created tasks that required cooperation. The boys had to work together to fix a water supply problem, push a broken truck, and pool money for a shared movie. Slowly, hostility melted away. By the end of camp, the Eagles and Rattlers were sharing meals and even riding the bus home together.

So What Does This Mean for Parents, Workers, and Teams?

For Parents (Sibling Rivalry Edition)

• Swap Monopoly for cooperation games: Instead of games that crown one winner (and three sulky losers), try games like Pandemic or Forbidden Island, where kids win by working together.
• Family missions: Give siblings a joint challenge—like building a blanket fort, baking a cake together, or planning a family picnic. They're more likely to focus on the task than on who's bossing who around.
• Common identity: Use language like, “We're all part of the Smith family team!” or even create a family mascot or crest. It sounds silly, but it makes “us” bigger than “me vs. you.”

For Workers (Office Politics Edition)

• Shift the lens: Instead of “Marketing vs. Sales” or “IT vs. Admin,” reframe as “We're all part of XYZ Company working towards growth.”
• Shared projects: Put people from different teams on the same project with a shared goal. Nothing builds bridges like needing each other to succeed.
• Celebrate joint wins: Highlight cross-team achievements publicly, so cooperation feels valued.

For Kids at School

• Class pride over year rivalries: Encourage teachers or parents to talk about “our school” instead of “Year 5 vs. Year 6.”
• Buddy systems: Pair kids across years or classes for joint projects, sports, or mentoring.
• Co-host events: Get different classes responsible for one shared school event—like a fair or fundraiser.

Make the “Us” Bigger Than the “Me”

Whether you're refereeing kids in the living room or navigating coworker tension at the office, the principle is the same: competition creates conflict, but cooperation builds connection.

Next time you sense rivalry brewing, ask: How can we make this a shared task? How can we create a bigger “us” that everyone belongs to?

Turns out, the secret to peace at home, school, or work might just be less Monopoly and more teamwork.