Macaques are a fascinating breed of monkeys. They have specific social interactions that closely mimic human ones.
When you observe a group of polite people as they talk, you can clearly see that they take turns talking and that they adjust the timing of their responses accordingly to what the other side is saying.
A team of Japanese ethnologists observed 15 adult females as they had a 20-minute vocal exchange. They noticed that the monkeys adjusted their conversational pauses so that they correspond to the timing of the answers from the other monkeys in the group.
Macaques possess the same instruments necessary to form humanlike words, but their brain is not developed enough to mimic human talk. This is why it is unclear whether what the Japanese scientists witnessed is, in fact, a monkey conversation.
What scientists did notice is that the pauses between grunts and coos from the monkeys corresponded to the breaks in human chats. The scientists saw that the length of the pause between the end of one monkey’s calls and the beginning of another were about 250 milliseconds which is similar to the average 200 milliseconds which occur during a conversation between humans.
This told scientists that the macaques are not just calling out for no reason. They seem to be taking turns while vocalizing. Their vocalizations are dynamic and conversational in nature.
This is the first instance where scientists studied monkey vocalizations that have a degree of social context and function. This closely resembles human speech, and this might reveal how the language of our ancestors evolved from the prelinguistic communication to the way we hold a conversation today.
The biggest issue with these findings is that something similar has been recorded in speech patterns of marmosets with the most significant problem being that the gaps between the interactions were three to five seconds long on average.