In March 2024, with the generous support of Gordon Getty, the Gruter Institute convened a group of evolutionary biologists, behavioral scientists, historians, economists, and legal thought leaders for “KissCon,” the first known interdisciplinary examination of the role of kissing and social contact from a scientific perspective. Convened at the Royal Society in London, KissCon examined the history of philematology across disciplines ranging from ancient history and evolutionary biology to the most recent pandemic and modern medicine. Following KissCon at the Royal Society, participants indicated significant interest in convening again on this subject with the opportunity for publication.
In February of 2025, we re-convened on this topic, this time at the home of Gordon Getty. Thanks to the leadership of Debra Lieberman, Editor in Chief of the journal Evolution and Human Behavior (EHB), EHB will publish a dedicated journal edition on this subject, which will include papers from the conference. In addition, a summary of the talks from this event will be shared here in the coming months.
KissCon developed several themes, starting with the role of kissing and other close physical contact as ways to facilitate biome sharing across populations. The practices themselves then appear to evolve as markers in affiliative contexts, across multiple species. These contexts include infant care, familial kissing, sexual signaling and arousal, and even hierarchical affiliation. Kissing signals interest, health, and mutual investment. Cultural acceptance, adaptations, taboos and laws around kissing and other close biome sharing practices may build on strong but yet undescribed physical signals that indicate physical health and interpersonal micro- expression and social exchange.
Kissing represents perhaps the highest rate of pathogen exchange between humans and plays a significant role in both mate assessment and bonding mechanisms. Understanding kissing and other proximate human to human contact in an evolutionary context provides critical information about the role of pathogen exchange in the context of the immune system. What do we know about the effects on the immune system when pathogen exchange via either kissing or proximate human contact decreases or increases? What are the impacts on human behavior when such pathogen exchange decreases or increases? What do we know about the role of the five senses being employed in both kissing and in proximate human contact? What forms of contact are platonic, and what is the role of physical attraction in such behavior? How is human contact mediated by social and cultural norms? How has it been regulated and controlled by law? Not all close contact is welcome or appropriate. Legal and societal rules and expectations are changing here as well. When a Spanish soccer federation official kisses a winning player, is this exuberance or abuse, what are the standards for capacity and consent?
These topics are not only of high interest in evolutionary theory, but they are critical to understand as humans in the increasingly isolated, digital, post-COVID-19 pandemic world. When kissing is viewed abstractly as one end in the continuum of human contact, it leads to broader questions about human interaction.
During the pandemic, most countries mandated reduced pathogen exchange, particularly outside of immediate family members. But it is the digitization of our lives, which started before the pandemic and has continued at marked speed since the pandemic, that appears to be having an even more robust and seemingly permanent negative effect on the extent to which we engage in face-to-face proximate human contact. Consider the number of non-family members a person typically encounters in a given day today versus 50 years ago. While in many parts of the world this may have increased in some more passive contexts such as public transport, it appears to have decreased in other more active social contexts such as in-person work and in-person gatherings.
Consider further the decreased use of the five senses in the “social” encounters that we have when such encounters are done virtually. With AI and the “attention economy” having their own Cambrian Explosion, reduced face-to-face encounters and isolation – what we might consider the opposite of kissing – will only increase. What are the implications of such “environmental change” for human society, including our immune systems, mental health, law, and institutions? What insights might we gain for technology and institutional design?
