The japanese macaques Macaca fuscata that live in the wild on the Japanese island of Koshima are of special interest in the areas of the ethology, the psychology, the anthropology and the human evolution because they were the first animals in which cultural traits similar to some human behaviors were identified.
In order to analyze the ability of these primates to understand the look and the state of care of other individuals, the researcher from the CEU Cardenal Herrera University (CEU UCH) of Valencia, Alba Castellano Navarro, has done three experiments in the natural habitat of these animals, under the direction of the professors of the Ethology and Animal Welfare Unit of CEU UCH, Federico Guillén and Anna Albiach.
The Japanese macaque is a suitable species to understand the origin and evolution of this human capacity in previous evolutionary stages
The results of this work, carried out in collaboration with researchers from the Max Planck Institute for Evolutionary Anthropology in Leipzig, in Germany, and the University of Kyoto, in Japan, allow us to better understand the evolution of the human capacity to interpret the gaze of other individuals. to determine their degree of attention and intuit their intentions.
According to Castellano, “the ability to interpret the gaze of another individual is a key aspect to understand how this factor has influenced human evolution and its ability to survive as a species. The japanese macaque it is a suitable species to understand the origin and evolution of this human capacity in previous evolutionary stages, as it is a phylogenetically more remote species than other primate species already studied ”.
There are also no previous studies that analyze these aspects in primates in a context of freedom and in their own natural habitat, as it has been possible to do in the study published in Scientific Reports during the seven-month stay on the Japanese island of Koshima.
Three experiments: threat, cooperation, competition
Experiments with macaques in their natural habitat have made it possible to evaluate the ability of these animals to interpret the human gaze in three contexts: threat, from cooperation and of competition.
The gaze is an important source of social information for the human species and also for other animal species, because knowing how to interpret it favors other capacities such as escaping a threat
“The animals interpreted the direct gaze of an approaching human as a sign of danger, showing greater flight distance and more threats towards him in this condition than when the human looked in another direction. They also adapted their behavior to the attention signals of a human who gave them food, moving to position themselves in their visual field ”, says the researcher.
However, the macaques did not seem to understand the visual perspective of a human competing with them for food, since they tried to recover both the food that was visible to the human and the one that was not.
“Together, our results support the idea that Japanese macaques can respond to a human’s gaze flexibly, depending on the context. Furthermore, they highlight the importance of studying this aspect of behavior in various species and contexts to better understand the selection pressures that may have led to their evolution ”, highlights the doctor from CEU UCH.
The analysis of these results, carried out by the CEU UCH research team, the Max Planck Institute and the University of Kyoto, sheds light on the evolution of the cognitive process known as Theory of mind, which explains the ability to interpret the intentions and wishes of others to act accordingly. A capacity that is only typical of highly social species.
“The gaze is an important source of social information for the human species and also for other animal species, because knowing how to interpret it favors other capacities such as escaping a threat. In addition, detecting the object of attention to which the gaze of another is directed can be crucial in contexts of competition and cooperation, such as those that we have proposed in our experiments with Japanese macaques, in the wild and in their natural habitat, a context in the there are hardly any previous studies ”, explains the researcher.
Alba Castellano et al. “Japanese Macaques’ (Macaca fuscata) sensitivity to human gaze and visual perspective in contexts of threat, cooperation, and competition”. Scientific Reports
Fountain: CEU UCH
Rights: Creative Commons.