Female chimpanzees carry sticks with them at the Kiber National Park in Uganda.
There is nothing obvious unusual about a chimpanzee being a smart tool
Users who use sticks as detectors, projectiles and spears.
But these chimpanzees don't do much to their sticks, they just hold and cradle them while they do their daily work.
Sonya kalenberg and Richard wranham think they know why.
They suggested the stick.
Carrying a chimpanzee as a mother.
Their sticks are the equivalent of human dolls, which the chimpanzees use as fake babies.
It may look like a far away
The idea is far-fetched, but the reasons for the two are strong.
First of all, there is no other obvious use for these sticks.
Kalenberg and Langham spent 14 years observing the chimpanzees in the kibale Kabs Kanyawara community.
At that time, they had seen the ape use the stick in various ways, but for about 40% of the time, they carried only the stick (
Or fragments of bark, logs or vines)
No obvious ending.
These sticks are often twice as thick and long as they are used as detection tools, and chimpanzees often carry them when they do a lot of things.
Some people even hold sticks while they sleep.
In addition, women carry sticks more often than men (
Even if they are generally less likely to use sticks).
It is also a young woman carrying a stick.
It is only when adults do not have their own children that they do so.
Although the mother did use the stick as a tool, they never carried a stick on purpose.
Without any form of teaching by adults, it is likely that young people will learn behavior from each other. (
This is attractive in itself, because the game traditions between children, such as nursery rhymes and games, can only be seen in humans. )
Karen Berg, wrenham and others have even noticed several examples of chimpanzees treating sticks in the mother's way. One (a male)
Even made a separate nest for his stick. Another (a female)
When her mother did the same thing to her sick siblings, she began to shoot her logs.
Overall, the sticks do seem to be prepared for future babies.
Richard Byrne, who studies the culture of chimpanzees at the University of St Andrews, said I think it is difficult to explain it in other languages (more obvious)ways.
Females, for example, often use sticks to catch termite.
But the object chosen to carry for this stick is obviously not like an insect-
Fishing tools, said Byrne.
Again, the weight of the stick is certainly enough to throw it out as a weapon, but it is the behavior of adult men, not young women.
However, Byrne wants to know, I want to know why young women choose not
Baby property.
I think little girls prefer soft and round dolls like babies.
Is there really nothing more in the wild chimpanzee environment than the doll? like? Moss bundles? Dead animals?
He even mentioned the case of a young chimpanzee (mostly female)
Show concern for a dying baby leopard beaten by an adult male chimpanzee.
If the explanation of kalenberger and Langham is correct, this is the first evidence that wild chimpanzees play with objects in different ways according to gender.
Not just one of them.
Human boys and girls like to play with different types of toys from an early age, boys prefer cars and weapons, and girls prefer dolls.
Some scientists believe that these differences are social.
Parents push specific types of toys to their babies according to social norms.
Many studies have documented this, but this is clearly not the case with Kanyawara chimpanzees, whose mothers never carry sticks.
Others argue that human toy preferences reflect some of the basic biological differences between genders.
In fact, even if the baby is only a few months old, these differences will appear, even in countries such as Sweden that emphasize gender equality.
Most importantly, the two little monkeys show the same gender difference in the bias towards human toys, although these are clearly not part of their natural environment.
I don't know why.
Maybe female babies are more interested in other babies, while men are more keen on roughand-tumble play.
Perhaps this is an example of texture: male babies are attracted to the hard angles and surfaces of vehicles and weapons, while women prefer soft toys.
If the gender difference is as clear as suggested, it is too clear.
Some studies have found that boys and girls have their own biases against toys. Others (
Including a monkey study)
I found that men are attracted to traditional "male" toys, but women will have fun playing with anything.
Among chimpanzees, young females have a special liking for sticks.
But it's not clear if the young male chimpanzee is biased against another game.
These conflicting results make it difficult to assess the final claim of Karen Berg and Langham: The Stick --
Carrying may represent the ancient gender differences that we had before we split with chimpanzees.
Social pressure of modern human beings.
If that's the case, it's hard to understand why to stick --
Never seen carrying in other populations of chimpanzees.
In terms of the gender difference in toy selection, it seems that the chimpanzee has more questions than the ones answered.
Update: Brandom Keim from Wired has a good idea of the story.
This is a kind of smart news that is both evaluated and analyzed.
However, the significance of this study may be difficult to analyze simply.
Although there are anecdotal reports that captive chimpanzees treat sticks as dolls, this behavior has never been reported in the wild.
At present, dolls are unique in their inventions and cultures.
Chimpanzees are also easily considered snapshots of the early stages of human development.
But chimpanzees have also evolved in culture and biology.
It has been 7 million years since our primate tree branch split.
Perhaps the Kibale chimp doll represents our own echo, but an example of cultural integration, where two species develop the same behavior separately, like the biological features of wings and eyes evolved in a similar but independent way.
No matter what the origin of playing with dolls is, it seems to be with tools, sadness, love and war, and is also common to humans and chimpanzees.
Reference: Current Biology;