Recent research has sought to clarify whether kissing originates from a grooming behavior among primates. While the social behaviors of primates share many similarities with kissing, there remains considerable debate about whether humans inherited this affectionate expression from their ancestors.
Kissing in Human Social Life
In human society, kissing is not only a way to express affection but also carries significant ritualistic and cultural rules. The ancient Romans had different types of kisses depending on the context and level of intimacy, for example: osculum was a kiss on the cheek symbolizing social affection; basium was a kiss on the lips among family members; and savium had a distinctly sexual connotation. Kissing rituals also vary widely around the world, from two kisses on the cheek in Europe to ceremonial kisses, such as kissing rings or hands.
Kissing is not only a way to express affection but also carries significant ritualistic and cultural rules. (Illustrative image).
The Origin of Kissing
A study led by Adriano R. Lameira from the University of Warwick examined how the grooming behaviors of primates might serve as an evolutionary foundation for human kissing behavior. According to Lameira, these behaviors—particularly the act of grooming with protruding lips and gentle sucking motions to remove parasites—could represent a primitive form of “kissing.” This leads to the hypothesis of the “true kiss”—suggesting that mouth-to-mouth kissing is an evolutionary behavior aimed at enhancing social bonds among primates.
As the lips and mouth are sensitive parts of the body, grooming behaviors through mouth contact may have become a pleasurable experience that reinforces relationships between individuals.
Is Kissing a Cultural Behavior?
However, whether kissing is a biologically rooted behavior or merely a cultural invention remains a contentious issue. A 2015 study across 168 cultures found that only 46% of these cultures engage in romantic kissing. Many indigenous hunter-gatherer societies do not kiss at all, and some cultures even find the act to be disgusting. This raises the possibility that kissing may be more of a Western-centric trait rather than a universal human need.
The Future of Kissing Research
Lameira suggests that further research into primate grooming behaviors could help clarify the role of kissing in strengthening social relationships and reveal lingering characteristics from our common ancestors with primates. However, to understand whether kissing is a natural or cultural behavior, more studies are needed to compare kissing and grooming behaviors across a wide range of primate species and different human cultures.
The findings of Lameira’s research were published in Evolutionary Anthropology, opening a new approach to understanding one of humanity’s oldest social behaviors from the perspectives of evolution and culture.
