Lip-on-lip kissing, an act often portrayed as a universal symbol of romance and intimacy, might not be as globally practiced as commonly believed. While deeply embedded in many cultures, the question of Why Do Humans Kiss remains a fascinating area of exploration, revealing diverse perspectives on this intimate behavior. Is it purely learned, or is there a deeper biological imperative driving us to lock lips?
Kissing: A Surprisingly Uncommon Custom
A comprehensive study analyzing 168 cultures worldwide revealed a surprising truth: lip-to-lip kissing in a romantic context is not a universal human behavior. Research led by William Jankowiak, an anthropology professor at the University of Nevada, Las Vegas, indicated that less than half – only 46% – of these societies engage in romantic lip-to-lip kissing. This figure excludes parental kisses or greetings, focusing specifically on intimate, romantic expressions. This discovery challenges the assumption of kissing as an innate human instinct and prompts us to delve deeper into the potential origins and purposes behind this behavior in cultures where it is practiced.
Evolutionary Roots: Breastfeeding and Nurturing
Two prominent theories attempt to explain the human inclination to kiss by linking it to early infancy and our innate responses as babies. One theory proposes that the pleasure derived from lip touching originates from the association with breastfeeding. This fundamental act of nourishment and comfort during infancy may create a lifelong positive association with lip contact.
Another intriguing suggestion connects kissing to “premastication food transfer“. This practice, observed in chimpanzees and other great apes, involves mothers pre-chewing food for their young and transferring it mouth-to-mouth. It’s hypothesized that early human mothers might have engaged in similar behavior, fostering a bond between mother and child through lip-to-lip contact and associating it with care and sustenance.
Beyond the Lips: Diverse Expressions of Intimacy
For cultures where lip-on-lip kissing is not the norm, intimacy and affection are expressed through a variety of other sensual practices. Sheril Kirshenbaum, an author exploring the science of kissing, highlights the “Malay kiss” described by Darwin. This involves women squatting while men lean over to take a quick sniff of their partner, essentially sampling their scent.
On the Trobriand Islands, an alternative form of intimate kissing involves lovers sitting face-to-face and gently nibbling each other’s eyelashes. While this might seem unconventional by modern Western standards, it served as a meaningful expression of intimacy for the Trobrianders. These examples underscore that the essence of kissing, in its broadest sense, is about sharing close, personal information and establishing an intimate connection, regardless of the specific physical act.
The Science of Scent: Information Exchange Through Kissing
Humans, unlike many animals with far more developed olfactory senses, may have evolved kissing as a way to get close enough to a partner to effectively “sniff” them. Scent plays a crucial role in conveying a wealth of information, including diet, health status, mood, and even genetic compatibility. By engaging in close facial contact during a kiss, we are subconsciously gathering and exchanging these subtle chemical cues. This theory aligns with the observation that many animals, with their superior sense of smell, do not require the close proximity of kissing to gather such information.
In conclusion, the question of why do humans kiss is multifaceted and does not yield a single, simple answer. While not a universal behavior, kissing in humans likely stems from a combination of evolutionary factors, potentially rooted in early nurturing experiences and the biological imperative to assess mate suitability. Furthermore, the diverse forms of intimate behavior across cultures highlight that the core purpose of kissing extends beyond just the physical act of lip contact. Ultimately, kissing, in all its variations, serves as a powerful tool for human connection, communication, and the expression of intimacy.
