A new study reveals that orangutans speak languages that are influenced by their social groups. Researchers studied the vocal calls of one of the four types of great apes in Borneo and Sumatra in Southeast Asia. They found that these critically endangered species have distinct vocal personalities that depend on social interactions in their group, just like humans.
High-density groups of orangutans have more original and unpredictable vocal calls than low-density orangutan groups, MailOnline reported. This study debunks previous beliefs that animals mingle with each other using a fixed repertoire of instinctive, automated calls.
Orangutan Calls Help Scientists Discover Origins of Language
According to Britannica, Hominidae is one of the two living families of the ape superfamily Hominoidea. Hominidae consists of four great apes, namely orangutans, gorillas, pan (bonobos ad chimpanzees), and Homo (humans). All of them share complex cognitive attributes, such as recognizing oneself when looking at the mirror.
However, orangutans are quieter than other apes and generally journey through the forest alone. As MailOnline reported, orangutans were the first to diverge from the great ape lineage and the only great ape aside from humans that uses vowel and consonant-like sounds in a complex manner.
Dr. Adriano R. Lameira, an assistant professor at the Department of Psychology at the University of Warwick, said that studies on both captive and wild orangutans help scientists resolve one of the longest-standing puzzles in science - the origins of language.
Dr. Lameira, who led the study, added that the new research allows them to start conceiving a gradual path to how humans learned to talk instead of using divine intervention, advanced cognition, or random genetic jackpot as the reason for humans' unique verbal skills.
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Socialization Significantly Shaped Languages of Orangutans
According to Science Daily, Dr. Lameira and his research team lived alongside orangutan communities in the swamps and low rainforests in Borneo and Sumatra in Southeast Asia to study their vocal behaviors. The research team recorded the vocal calls of 70 individual orangutans across six populations and analyzed them.
They observed that populations of each orangutan group differed naturally in population density. They either socialized intensely or are more dispersed. In people with high density, orangutans seemed to communicate in a large variety of vocal calls and try out new vocal sounds that were continually modified or dropped.
On the contrary, low-density populations favor the more established and conventional calls and do not usually experiment with a variety of novel sounds. But in cases when they introduce a new call variant, they tend to keep them, making their repertoire more organized and richer than high-density populations that constantly discard new call variants.
Researchers noted that this is similar to how human languages are shaped. They believe that social influence could have increased steadily, that ultimately led to myriad ways in which language is determined by the surroundings. Dr. Lameira added that more clues are waiting to be unraveled from humans' closest living relatives as long as orangutans are preserved in the wild to maintain the evolutionary history of great apes.
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