There is an astonishing variety of greetings between humans in the world: Tibetans stick out their tongues; Maori touch their noses; the Ethiopians, the shoulders; and the Congolese, the forehead; in many Asian countries they greet each other without touching; and Arabs and Europeans hug or kiss each other on the cheek. Despite the heterogeneity and the recent effort of some English speakers, such as former President Barak Obama, to extend the culture of the fist bump , the most widespread form of greeting in the world is the handshake, which originated in Greece in the 20th century. V BC to show that neither of the interlocutors carried a weapon.
As always and as you can suspect from the title of the article, humans are not the only ones to practice different greetings with our fellow human beings. Researcher Edwin JC van Leeuwen from the University of Antwerp, Belgium, published a study in May 2021 in the journal Biology Letters , in which he followed two groups of chimpanzees with different styles of handshake while holding for twelve years. groomed.
The discovery of this behavior was first described in 1978 by William McGrew of the University of St. Andrews, Scotland, and never before has it been tracked as enduringly as that of van Leeuwen. Although the function of the handshake in chimpanzees is unknown at the moment, the author of the study compares them with human handshakes, as if it were a cultural and social behavior. Although he suspects that these greetings could play a critical role in social bonding, this fact has yet to be proven, just as it would not have any known benefits in terms of survival, fitness, or group identification.
“Within the two groups, female-female chimpanzee pairs were more likely to put their hands palm-to-palm, while male-male pairs were more likely to put wrists together, potentially to assert dominance,” van Leeuwen tells The Scientist . Something curious is that despite the changes of individuals in the two groups studied, whether due to transfer or death, the greetings of each group were maintained over time and the new incorporations were learning them.
Due to our genetic proximity, in his study, van Leeuwen bets on the existence of a potential link between this cultural behavior in chimpanzees, their ability to learn and maintain new customs, and the history of the evolution of human social behavior. “The motivation to learn socially is most likely a generalized phenomenon that is stimulated by similar selection pressures and preserved phylogenetically”, says the scientist.
Despite the uncertainty, the scientist will continue to investigate groups of chimpanzees to better understand how the different handshakes are transmitted and what their function would be. “The difficulty of this study lies in the limitations of the observational data. We only see what chimpanzees show us. There may be many handshakes that we will never know, “ concludes van Leeuwen in The Scientist .
References:
van Leeuwen, EJC (2021). Temporal stability of chimpanzee social culture. Biology Letters, 17 (5), 20210031. https://doi.org/10.1098/rsbl.2021.0031
