Do humans naturally kiss?

Kissing is a common romantic and affectionate gesture in many human cultures, but does this mean kissing is an innate human behavior? There are several views on whether kissing is an instinctive act or a learned cultural practice. In this article, we’ll explore the evidence behind both perspectives.

The case for kissing being an instinct

Those who argue kissing is instinctive point to several pieces of evidence:

  • Kissing is seen in cultures worldwide, suggesting it serves an important evolutionary purpose.
  • People often feel drawn to kiss without being taught to do so.
  • Kissing activates reward regions of the brain, releasing feel-good chemicals like oxytocin, dopamine, and serotonin.
  • People tend to remember their first kiss vividly, hinting at its biological significance.
  • Primates like bonobos engage in kissing behaviors, implying an evolutionary origin.

Based on these points, some believe kissing is an inborn mating behavior selected for during human evolution. The pleasure and pair-bonding effects of kissing may have promoted more intimate, longer-lasting relationships between parental figures, improving the survival of offspring. This would explain why humans possess dedicated nerve pathways in the lips and mouth optimized for kissing interactions.

The case for kissing being a learned cultural practice

Despite the biological arguments, many anthropologists view kissing as primarily a cultural invention. Reasons for this include:

  • Kissing behaviors vary enormously between cultures in terms of meaning and context.
  • No historical accounts of kissing exist prior to written records 5000 years ago.
  • Children don’t spontaneously kiss without being taught to do so.
  • Many cultures show no evidence of kissing or consider it repulsive.
  • Kissing doesn’t seem critical for reproduction, unlike sex.

According to this position, the act of pressing lips to another to express intimacy is not instinctive, but socially constructed. While humans may have a general propensity for intimate mouth contact, the specific forms it takes are invented rather than innate. For example, mouth-to-mouth kissing doesn’t efficiently transfer chemicals, making it implausible as an evolved mating mechanism. Overall, the variation in kissing practices and their late emergence argue against their evolutionary origin.

Evidence that kissing is innate but shaped by culture

As is common in psychology and anthropology, the truth about kissing likely lies somewhere between the two extremes. In particular, some evidence suggests humans possess an inherent motivation to kiss but culture influences how it manifests:

  • Kissing seems pleasurable and meaningful across cultures, hinting at innate drivers.
  • At the same time, who people kiss and specific techniques vary culturally.
  • Infants exhibit mouth-oriented behaviors, but parents determine if these become kisses.
  • Kissing may have evolutionary origins but culture elaborates on it.
  • Bonobos kiss, but not identically to humans, showing inborn and cultural factors.

From this perspective, kissing does not seem to be a fixed action encoded in our genes, but neither is it entirely constructed by culture. Human brains probably have a flexible preference for intimate mouth contact that manifests differently in various ecological and social contexts. How this mouth contact gets molded into “kissing” depends on learning and community practices, even if the urge to kiss stems from our biology.

Cross-cultural examples of kissing behaviors

To better illustrate the interplay between innate kissing motivations and cultural variations, here are some examples of kissing practices from different societies:

Society Kissing Practices
Japan Kissing is considered intimate and typically avoided in public. Young people kiss more often than older generations.
Netherlands Kissing friends on the cheeks is customary when meeting or parting.
Thailand Kissing is frowned upon between people of different status. Kissing the feet of monks demonstrates respect.
South American tribes Passionately kissing with open mouths was unknown before contact with European explorers.
North African tribes Spitting into each other’s mouths was a common greeting.

This small sample demonstrates the diversity of kissing taboos, norms, and meanings across cultures. From romantic to reverent to nonexistent, kissing clearly represents more than just a biological instinct.

The instinct to kiss may vary between individuals

Not only does kissing differ between cultures, natural motivations toward it seem to vary between individuals as well. Those on the asexual spectrum, for example, often report little desire to kiss and find it unappealing. This indicates social and biological factors intersect at the individual level too.

Genetics that influence hormone systems like oxytocin and testosterone levels may impact kissing inclinations to some degree. Upbringing and cultural background interact with this inborn variability, complicating simplistic nature versus nurture explanations.

A hypothetical innate kissing drive manifests to differing extents in each person based on multiple biological and environmental inputs. For most, this drive is probably strong enough to motivate kissing behavior given the right cultural support.

Kissing serves social and evolutionary functions

If kissing does have some innate roots, how might it have evolved? And what purposes does it continue to serve?

Many propose kissing provides health benefits that improve bonding and reproduction. Through close physical contact, partners share beneficial microbes that bolster immune systems. Saliva exchange may also allow partners to chemically assess biological compatibility for mating. The touching of lips transmits signals about gender, reproductive status, and genetic quality as well.

These possible bio-evolutionary functions may motivate innate kissing desires, but more overt social purposes help maintain the behavior culturally. Kissing demonstrably facilitates pair bonding, emotional intimacy, and relationship satisfaction. The greater neurological, physiological, and emotional engagement kissing requires compared to more casual touch seems adaptive for reinforcing long-term attachments between parents. This would promote the family stability and paternal investment necessary for raising fit human offspring.

Kissing also functions as a mate assessment device. The close physical proximity kissing necessitates allows details about potential partners to be gathered. The willingness to engage in kissing signals relationship interest and availability. Thus beyond biological contributions, kissing clearly facilitates the social evaluation of mates needed for optimal partner choice.

Kissing and sexual consent

While kissing has innate motivations, cultural norms around how to kiss ethically have arisen over time. Issues of consent, harm avoidance, and power dynamics come into play.

One should not automatically assume others want to be kissed based on a personal urge to do so. Establishing mutual interest, ideally through verbal communication, helps avoid nonconsensual contact. This is especially important between unfamiliar individuals where unwanted kissing can be experienced as threatening or degrading.

Even within established relationships, consent should be maintained as kissing preferences can change over time. Partners should periodically check-in to determine if kissing is desired by both parties in that moment. Kissing should not be coerced through emotional or physical force as an expected obligation.

Cultural consent standards also discourage kissing that exploits power differentials. Kissing between adults and children, teachers and students, or employers and employees often constitutes inappropriate conduct. The inherent intimacy of kissing increases risks of harm when large status imbalances exist.


In summary, the origins of kissing likely involve both innate neurobiological factors and varied cultural elaborations. Human brains appear predisposed to enjoy intimate mouth-to-mouth contact. But culture determines appropriate contexts, styles, and meanings for manifesting this desire into reciprocal “kissing” behaviors.

The blend of biological reward pathways and social learning involved makes kissing challenging to categorize as strictly instinct or culture. Like many human behaviors, it stems from ancient evolutionary impulses but gains sophisticated nuance through our collective ingenuity and cooperation.

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