A kiss is just a kiss, right? Well, not exactly.
Kissing someone can be an intensely intimate exchange — conveying our deepest emotions when words can’t quite do the trick.
But why do we humans kiss? How did it all begin? And most importantly, what makes it so intensely amazing when the chemistry is right? Let’s dive into the lip lock.
One popular theory about kissing’s origins relates to how our ancient ancestors looked for food. Anthropologists say the most successful foragers were the best at detecting reddish colors, leading them to the ripest fruits and berries. Over many generations, this skill naturally evolved into the belief that “red equals reward.”
So wherever a shade of red popped up, our primate ancestors perked up. One of the most obvious places it could be seen was on the backsides of females — whose rear ends turned bright crimson when they were ready to mate.
In his book The Naked Ape: A Zoologist’s Study of the Human Animal, zoologist Desmond Morris suggested that in much the same way, a woman’s lips evolved to signal sexual receptiveness.
Morris tested his theory by showing male volunteers photos of women wearing different colors of lipstick. He asked the volunteers to rate the attractiveness of each.
The men consistently chose women wearing the brightest red lipstick as the most appealing (think Taylor Swift). This preference suggests that even today, our modern brains link full, rosy-colored lips to a woman’s reproductive capacity.
Although it’s practiced widely today, romantic kissing might not be an instinctive human behavior. Instead, scientists say, it likely developed as a learned mating behavior.
According to Troel Arboll, a professor of Asian history at the University of Copenhagen, Denmark, the first evidence of lip kissing is from a text from ancient Iraq. Dating from around 2500 BCE, the text describes two male gods copulating and kissing.