People do it, primates practice it, even polar bears participate in it. Currently, scientists have reconstructed the evolutionary beginnings of kissing.
This research indicates that the mouth-on-mouth contact developed more than twenty-one thousand-thousand years ago, and was a behavior that the common ancestor of humans and other large primates likely indulged in.
This study concluded that ancient humans may have engaged in kissing as well – and that modern humans and Neanderthals might have smooched each other.
By finding evidence of additional animals practicing mouth contact, researchers could build an "evolutionary family tree" to determine when it was most likely to have developed.
To make certain that they were examining the same behaviour across different animal types, the scientists had to give a very precise – quite clinical – definition to a "kiss".
In this research, released in a scientific journal, they defined oral contact as non-hostile, directed mouth-to-mouth contact "with some motion of lips or lips and without nourishment exchange".
"Humans, chimpanzees, and bonobos all engage in kissing," explained principal investigator the study's lead author. From that, she concluded, "it's probable that their most recent shared predecessor kissed."
"We think mouth contact likely developed around 21.5 thousand-thousand years in the past in the great primates."
In this study, researchers found behaviour that fit their scientific definition of kissing in canines, prairie dogs, arctic bears (very sloppy – lots of lingual contact), and including albatrosses.
The researchers concentrated on monkeys – and apes in specific – in an effort to build an evolutionary understanding of the beginning of the human kiss.
This research also found that ancient human relatives – our closest ancient hominid relatives that became extinct approximately 40,000 years ago – also engaged in kissing.
Earlier piece of research on Neanderthal DNA also revealed that modern humans and Neanderthals shared an oral bacteria – a type of microorganism found in our mouth fluid.
"That means that they must have been swapping mouth fluid for many hundreds of thousands of years following the two species split," commented the lead researcher.
While this research pinpointed the time kissing developed it was not able to answer the question of the reason.
There are numerous several theories – that it originated from grooming behaviour in our primate ancestors or that it could offer an intimate way to assess the wellness and including the compatibility of a mate.
The lead researcher expects that the study will open a door to solving that question.
"It's important for humanity to recognize that kissing is something we share with our animal relatives," she commented.
"Researchers ought to be studying this behaviour, rather than discarding it as silly because it has affectionate associations in humans."
