\n<\/p>\n
November 19, 2025<\/p>\n
3 min read<\/p>\n
Kissing May Have Evolved 21.5 Million Years Ago<\/p>\n
Humans and their ancestors have likely been kissing for a very long time<\/p>\n
By Stephanie Pappas edited by Jeanna Bryner<\/span><\/p>\n Photo by Stefano Bianchetti\/Getty Images; Illustration by Scientific American<\/p>\n For humans, kissing holds major cultural cachet, accompanying confessions of romantic love, religious rituals of reverence and even betrayals, \u00e0 la The Godfather Part II\u2019s \u201ckiss of death.\u201d<\/p>\n New research suggests that kissing probably predates humanity and evolved between 16.9 million and 21.5 million years ago, after the ancestor of the great apes split from the lesser apes, or gibbons. There is even evidence that Neandertals kissed.<\/p>\n \u201cKissing is a really interesting one because it\u2019s something humans seem to take for granted,\u201d says study lead author Matilda Brindle, an evolutionary biologist at the University of Oxford. Surprisingly, romantic kissing has been documented in only 46 percent of human cultures, she says. \u201cBut for those who do kiss, it\u2019s this everyday act that also has this huge cultural significance.\u201d<\/p>\n If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<\/p>\n Brindle and her colleagues, Catherine Talbot of the Florida Institute of Technology and Stuart West of Oxford, wanted to evaluate kissing from an evolutionary perspective. So they searched through past studies for modern examples of primates smooching, defined rather unromantically as \u201cnon-agonistic interaction involving directed, intraspecific, oral-oral contact with some movement of the lips\/mouthparts and no food transfer.\u201d They found that just like humans, great apes kiss for a variety of reasons, from conveying sexual desire to indicating friendly, affectionate feelings.<\/p>\n \u201cWhen chimps have an argument,\u201d she says, \u201cthey will often go and literally kiss and make up afterwards.\u201d<\/p>\n The researchers also found reports of kissing in all great apes, from humans to chimpanzees to orangutans, with the exception of the eastern gorilla. There were no observations of kissing in gibbons. Based on this taxonomy, the researchers estimate that kissing evolved after the great apes split from the lesser apes. This means that Neandertals and other human ancestors probably kissed. Bolstering this idea, preliminary evidence from DNA in ancient dental plaque has shown that Neandertals and humans shared oral bacteria until 112,000 years ago, hinting that they may have kissed each other.<\/p>\n The primate kissing observations were too fragmented to reveal much about how or why kissing evolved, however. Species that kiss tend to have mating systems in which females mate with multiple males, the researchers report in the new study, which was published in the journal Evolution and Human Behavior. Every species that kisses also engages in premastication, or chewing food before giving it over to another individual, which could be a precursor to kissing, Brindle says. There is a lack of data about premastication in species that don\u2019t kiss, however, making the link tenuous.<\/p>\n It\u2019s also unclear whether both platonic and sexual kissing have the same roots, says Zanna Clay, a comparative psychologist at Durham University in England, who researches primate behavior but was not involved in the study. Kissing during mating is less often observed in the wild than affectionate kissing, Clay says: \u201cThis study is working with a relatively limited dataset.\u201d<\/p>\n Primate researchers haven\u2019t focused much on primate kissing, Brindle concurs, saying the paper is a \u201ccry\u201d for researchers to collect more data. \u201cIt\u2019s really exciting that we\u2019ve traced the evolutionary history of kissing back to 21.5 million years ago,\u201d she says, \u201cbut we could do so much more if we had additional data.\u201d<\/p>\n If you enjoyed this article, I\u2019d like to ask for your support. Scientific American<\/span> has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.<\/p>\n I\u2019ve been a Scientific American<\/span> subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm <\/span>always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.<\/p>\n If you subscribe to Scientific American<\/span>, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.<\/p>\n In return, you get essential news, captivating podcasts, brilliant infographics, can’t-miss newsletters, must-watch videos, challenging games, and the science world’s best writing and reporting. You can even gift someone a subscription.<\/p>\n There has never been a more important time for us to stand up and show why science matters. I hope you\u2019ll support us in that mission.<\/p>\n","protected":false},"excerpt":{"rendered":" November 19, 2025 3 min read Kissing May Have Evolved 21.5 Million Years Ago Humans and their ancestors have likely been kissing for a very long time By Stephanie Pappas edited by Jeanna Bryner Photo by Stefano Bianchetti\/Getty Images; Illustration by Scientific American For humans, kissing holds major cultural cachet, accompanying confessions of romantic love,<\/p>\n","protected":false},"author":1,"featured_media":34538,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[6961,17226,6959,118,3698,13788,1305,637],"class_list":{"0":"post-34537","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-ancestor","9":"tag-apes","10":"tag-evolved","11":"tag-great","12":"tag-humans","13":"tag-kissing","14":"tag-million","15":"tag-years"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/34537","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=34537"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/34537\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/34538"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=34537"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=34537"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=34537"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}On supporting science journalism<\/h2>\n
It\u2019s Time to Stand Up for Science<\/h2>\n