We are searching data for your request:
Upon completion, a link will appear to access the found materials.
The ability to smile, and to do so in different ways by varying facial expressions, has a strong impact on the way human beings communicate. However, in primates it was not known if they could change the way they smile. Now a study published in the journal Plos One, which investigated 46 chimpanzees from the Chimfunshi Wild Animal Orphanage in Zambia, Africa, has revealed that these primates have the same types of smiles as humans.
This finding, made by scientists from different European institutions, including the University of Portsmouth (United Kingdom), suggests that the human smile evolved from the expressions of the apes to respond to positive attitudes.
"Human beings have the flexibility to smile, speaking or not speaking and laughing or not laughing, but until now we did not know if chimpanzees were capable of making these facial expressions without emitting any vocalization," says the study's lead researcher, Diana Davila -Ross from the University of Portsmouth.
A smile coding system To make these inquiries, the scientists developed ChimpFACTS, a standardized coding system that was applied to measure the facial movements of the chimpanzees who participated in the study.
"ChimpFACTS allows us to subtly examine facial movements and compare the facial expressions of humans and primates, based on their shared musculature," says study co-author Kim Bard.
This coding system investigated the types of smiles that are accompanied by sounds - laughter - and found that they have the same evolutionary origin as those of humans when they smile.
Data from "ChimpFACTS" showed that chimpanzees produce the same fourteen open-mouthed facial expressions both when they make present sounds and when they do not. In addition, according to the study, these primates use different expressions of smiles depending on what role they were occupying in social play with other individuals of their species.
In addition, according to the study, these primates use different expressions of smiles depending on what role they were occupying in social play with other individuals of their species. These findings support the idea that the use of chimpanzee smiles has a communicative meaning, the researchers point out. Bibliographic reference: Marina Davila-Ross, Goncalo Jesus, Jade Osborne, Kim A. Bard: “Chimpanzees (Pan troglodytes) Produce the Same Types of 'Laugh Faces' when They Emit Laughter and when They Are Silent ”. PLOS ONE (2015). DOI: 10.1371 / journal.pone.0127337.