LAWRENCE — Is a kiss just a kiss? Or is it a sign of love, affection, a biological urge, contract or even an assault? Law, history, evolution and anthropology show that it can be all those things.
A University of Kansas law professor has published an analysis examining the legal history of the kiss, tracing how views of one of the seemingly most basic of human behaviors are not universal, especially through a legal lens.
Andrew Torrance, Paul E. Wilson Distinguished Professor of Law at KU, is a member of the Gruter Institute for Law and Behavioral Research. The organization brings together scholars from law, biology, economics, behavior and other disciplines and chooses what Torrance described as “avant garde” topics for its conferences. Most recently, the society chose to explore the kiss.
For his part, Torrance wrote an examination of laws regarding the kiss, or “osculation regulation,” published in a special edition of the journal Evolution and Human Behavior.
“Lawyers like me often come at it from an angle of ‘somebody performed a kiss and somebody didn’t want that, so what does the law say,’” Torrance said. “It turns out the law of the kiss has a long, varied history.”
He began his research by examining evolutionary insights about kissing, pointing out various theories on why humans developed the behavior — including how it proved love was strong enough that participants were willing to risk sharing disease. Meanwhile, anthropological evidence showed wide cultural views on the value of a kiss, including how many cultures eschew the practice.
From this investigation, Torrance found kissing is not a universal practice. The legal regulations have not been universal, either.
The KU author then examined how throughout various legal histories, a kiss has been viewed as belonging in the realm of property, contract, tort and criminal law.
First, as property, legal history shows that kisses were often viewed as something that belonged to a person that could either be given or wrongfully taken, Torrance said. In some societies, a young woman’s kisses taken without consent of the patriarch could result in punishment of the aggressor or be seen as a sign of lost virtue.
Various legal traditions proceeded to view the kiss as part of contract law. All manner of partnerships, from marriages to businesses to illegal agreements, have been “sealed with a kiss.”
“What would it mean if a crime boss were to kiss the hand of another crime boss? It could be a sign of respect, a show of subservience to a superior or even a contract agreement. It’s a fascinating range of possibilities,” Torrance said.
Legal regulation of the kiss eventually evolved to a tort lens in which unwanted kisses were seen as a wrongdoing with potential criminal consequences. Today, unwanted kisses are viewed as assault or sexual assault in many societies around the world. Those views have themselves evolved from ways for the powerful to control others to progress in gender equality, Torrance wrote.
While variations of kissing laws have continued over the years, including Puritan “blue laws” about public displays of affection to open acceptance of such behavior, Torrance said there is still not agreement or equal application of such laws. In some cultures, public kissing is frequent, while in other areas of the world, it can land even consenting adults in legal peril.
Similarly, he said, application of the law has been inconsistent when regarding certain types of individuals, such as same-sex couples, and mixed-race couples have historically been arrested or punished for behaviors while others were not.
Ultimately, just as who kisses whom and their reasons for doing so have evolved, so have modern understanding and laws regarding the kiss, the KU researcher said. But, taken together, the fields of history, science, culture and the law can help one another understand the kiss and how it can be regulated without outdated moralism. It may even address cultural misunderstandings.
“The law is not just a set of rules that tries to constrict human behavior. It’s also a reflection of human values and how society views a certain behavior,” Torrance said.
Perhaps the future could be one where no one is punished for a loving kiss and no one has to endure an unwanted or “bad man’s kiss,” as it has been historically known, Torrance wrote in his conclusion.
“The ‘Bad Man’s Kiss’ is increasingly out of place, and the good person’s consensual kiss is recognized as a cherished liberty. In such a world, the law’s ultimate message about kissing might echo the gentle wisdom of evolutionary biology: It’s in our nature to connect, but it’s in our society’s interest to ensure those connections are consensual and kind. That sentiment can surely be sealed with a kiss.”
Evolution and Human Behavior
10.1016/j.evolhumbehav.2026.106917
Meta-analysis
Not applicable
OSCULATION REGULATION - THE LAW OF THE KISS
1-Sep-2026