Puits de Science #01: has Facebook always existed?

René Descartes and Charles Darwin wear their Youtubers' hats in Puits de Science, a series in which they address broad scientific questions. To find answers, they interview several experts and occasionnaly invite other historical figures of science.
Episode 1: Scientists are interested in social media and their impacts on the users' lives, but they are also studying social networks, which are actually older than one may think. The need to share and show oneself has existed since far before the invention of computers. For example, painted ceilings from the Middle-Ages have been discovered with representations of funny scenes and scenes from daily life. Moreover, that need to socialize does not only concern humans, but also any animal that lives in communities. From insects to monkeys, scientists have observed cases of social interaction, food sharing and grooming. All of these behaviours are due to the presence of a network.