Chimpanzees kiss after a fight, and people get their own nudge on National Kiss and Make Up Day, Wednesday, August 25, 2027. Science has plenty to say about patching things up.
Late August’s Peace Offering
August 25, each year. Who first proposed it was never written down.
How Making Up Got Studied
Chimps that reconcile
In 1975, a young Dutch zoologist named Frans de Waal began studying the chimpanzee colony at the Arnhem Zoo in the Netherlands. He noticed something after fights.
Former opponents came together to kiss and hug. De Waal called it “reconciliation,” a word that had been reserved for humans.
His 1979 paper with Angeline van Roosmalen laid out the pattern in the journal Behavioral Ecology and Sociobiology. Former rivals touched each other more often than they touched third parties, and they did it soon after the conflict.
Arnhem’s chimps used kissing to mark these peacemaking contacts. Hugging was more typical of consolation, when another chimp comforted the one that had been attacked.
Peacemaking Among Primates, his 1989 book, built on that work. De Waal died in March 2024 at 75.
De Waal once summed up his career this way: “I’ve brought apes a little closer to humans but I’ve also brought humans down a bit.”
An ancient habit
People have kissed for a very long time. Troels Pank Arbøll and Sophie Lund Rasmussen reported in Science in 2023 that cuneiform clay tablets show kissing in Mesopotamia 4,500 years ago.
The tablets describe lovers kissing. They also mention kisses among friends and family, and they push the earliest documented kissing back about 1,000 years.
Earlier research had placed the origin of lip kissing in South Asia 3,500 years ago. Arbøll argues kissing “should not be regarded as a custom that originated exclusively in any single region.”
Romantic kissing isn’t universal, though. A 2015 study in American Anthropologist found evidence of the romantic-sexual kiss in only 46% of cultures.
What Makes an Apology Work
For humans, making up usually starts with words. In 2016, Ohio State researchers led by Roy Lewicki tested six parts of an apology on 755 people in two experiments.
One experiment used 333 adults recruited online. The other used 422 undergraduates.
Acknowledging responsibility mattered most. “Say it is your fault, that you made a mistake,” Lewicki advised.
Second place went to an offer of repair in Lewicki’s ranking. Expressing regret, explaining what went wrong and declaring repentance tied for third.
Asking for forgiveness came last. “That’s the one you can leave out if you have to,” Lewicki said.
Written statements have limits, Lewicki acknowledged. Emotion and tone of voice in a spoken apology may matter too.
Overall, apologies with more of the six elements worked better. The Mesopotamian tablets and de Waal’s chimps show that kissing and making up both have long histories.
Ways to Make Up on August 25
- Open your apology by owning the mistake, the step Ohio State found mattered most.
- Offer to fix what you can, since “talk is cheap,” as Lewicki put it.
- Drop the request for forgiveness if it feels forced, because it rated lowest.
- Apologize face to face, where eye contact and sincerity can do their work.
- Follow the Arnhem chimps and reach out soon after a quarrel, not weeks later.
Frequently Asked Questions
Do other apes kiss?
Bonobos do too. Rasmussen suggests that may mean kissing is a fundamental human behavior.
What is the oldest image of a kiss in the study?
A Babylonian clay model from around 1800 BC shows a couple kissing.
Did ancient kissing spread disease?
Possibly. Mesopotamian medical texts describe an illness resembling herpes, but Arbøll warns they “cannot be read at face value.”
How did the Ohio State study test apologies?
Participants imagined hiring an accountant who had filed an incorrect tax return. They rated his apologies on a scale from 1 to 5.
Sources
- Behavioral Ecology and Sociobiology – Reconciliation and consolation among chimpanzees (1979)
- Emory University – Frans de Waal remembered (2024)
- University of Copenhagen – The earliest recorded kiss occurred in Mesopotamia 4,500 years ago (2023)
- Human Relations Area Files, Yale – Is the romantic-sexual kiss a near human universal?
- Ohio State University – The 6 elements of an effective apology, according to science (2016)