“I was surprised that Santino’s stone gathering drew so much attention. I think some of my other studies are actually more important. But the story about the stones was simple to describe and a bit dramatic”, says Mathias Osvath.
He explains that the stone throwing does not mean Santino is unhappy at the park.
“This is normal behaviour for chimpanzees. Santino is the leader and must assert his position, both for the other chimpanzees and for the visitors, every day.”
The other studies in the thesis address, among others, self-control in chimpanzees and orang-utans. They show that the apes, to the same extent as humans, choose a larger reward later over a smaller reward immediately. The apes can also imagine what a tool could be used for without having learnt to use it. Doing this requires that they can also recall memories of similar situations. In cognition science, all this is known as the ‘episodic system’.
“These apes can plan and ‘create’ the future in their mind’s eye. They can also picture future mental states, for example that they will need a tool to gather food when they become hungry. Or as in Santino’s case, even breaking up stones to have in readiness for the visitors’ arrival”, says Mathias Osvath.
He explains that there are some tests in which the primates do better than people.
“They have some memory functions that are better. For example, they are better at remembering a set of numbers that are shown very fleetingly. This is probably because such abilities are more important for apes in their living environment. We have a better memory for language instead.”
And in case you’re wondering: yes, apes can count.
Mathias Osvath thinks it’s actually strange that we have ever seen ourselves as the ‘crown of creation’.
“Almost every week new research findings are published that show that we are not as unique as we think we are.”
But if the apes have the ability to imagine, why have they not developed a language, with all the components we see in ours?
“This is largely because we live so differently. For us it is important to be able to cooperate. Apes do not have the same need for this. For them it is more the leader who plans and decides everything. However, we mustn’t forget that research has not been carried out into a lot of the apes’ language”, says Mathias Osvath.
What does he think about the apes’ emotions?
“The ability to imagine definitely means that the apes have emotions. But then I think at least all mammals and birds do.”
TEXT: Linda Viberg
Mathias Osvath defended his thesis “Planning primates – A search for episodic foresight” on 5 May 2010. Mr Osvath can be contacted by telephone, +46 (0)705 330674 or email, Mathias.Osvath@lucs.lu.se.