The diversity of greetings that exists among humans all over the world is great, from Maoris who touch their noses, to Ethiopians who touch their shoulders, Congolese their foreheads, Tibetans who touch their tongues and Arabs, Europeans and South Americans who speak hug or kiss on the cheek, even the non-contact of Asian countries that bow slightly.
While there are all these types of greetings, the most universally known is the handshake that emerged in Greece in the fifth century BC to show that they didn’t have a weapon.
And recently, wrist or elbow shock has been added to the COVID-19 pandemic framework.
But humans are not the only ones who greet each other with our peers, some animals do too and they were attended by researcher Edwin JC van Leeuwen, from the University of Antwerp, Belgium. The study he published in May this year in the journal Biology Letters, is a twelve-year accompaniment of two groups of chimpanzees with different styles of handshake during their preparation.
The discovery of this behavior was first described in 1978 by William McGrew of the University of St Andrews in Scotland and has never before been followed up as extensively as that of van Leeuwen.
Although the function of the handshake in chimpanzees is currently unknown, the author of the study compares it with the human handshake, as if it were a cultural and social behavior.
Scientists noted that groups of chimpanzees in Zambia had two different ways of doing this squeeze. While some held hands, others held their wrists.
According to van Leeuwen, the fact that “handshake” is not a family trait, but is learned within groups, indicates that chimpanzees have the motivation and ability to learn to incorporate social norms.
In other words, these greetings could have a fundamental role in the social bond, a fact that has not yet been proven.
The curious thing is that despite the changes of individuals in the two groups studied, either by transference or death, the greetings of each group were maintained over time and the new incorporations were learning.
Due to our genetic proximity, in his study, van Leeuwen bets on the existence of a potential link between this cultural behavior of chimpanzees, their ability to learn and maintain new customs, and the history of the evolution of human social behavior. “Motivation to learn socially is likely a pervasive phenomenon that is stimulated by similar selection pressures and is phylogenetically preserved.“Says the scientist.
Despite the uncertainty, the scientist will continue to investigate groups of chimpanzees to better understand how different handshakes are transmitted and what their function would be. “The difficulty of this study lies in the limitations of observational data. We only see what chimpanzees show us. There may be a lot of handshakes we’ll 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