Competition and Cooperation in Language Evolution: A Comparison Between Communication of Apes and Humans - Conflict and Multimodal Communication: Social Research and Machine Intelligence - page 94

The results showed that chimpanzees were more likely to give alarm calls in
response to a snake in the presence of unaware group members than in the presence
of aware group members. According to the authors “chimpanzees keep track of
information available to receivers and intentionally inform those who lack certain
knowledge [ ::: ]. [They] communicate missing information that is relevant and
beneficial to receivers ” (Crockford et al. 2012 : 145, our emphasis). In others words,
chimpanzees are able to monitor the information available to others: they recognize
knowledge and ignorance in others and control vocal production to selectively
inform them. They inform ignorant group members of danger with such reasoning as
“I know something that you don't know, and I know that this information is useful to
you.” At the same time, the receivers are able to understand the informative intent of
the signalers, even if not directed to themselves. After an individual produced alert
calls to inform another individual that was behind his shoulder and some 10 m away
and that had not seen the snake, the ignorant chimp stopped traveling, revealing to
have grasped the communicative intent of the signaler.
Similar results were obtained by Schel et al. ( 2013b ). The authors presented wild
chimpanzees with a python model and found that most alarm calls met key criteria
for intentionality. Specifically, the results showed that the alarm calls were produced
in the presence of socially important individuals: production was significantly
mediated by the friendship between the caller and the arriving individual, with
the arrival of friends more likely to be associated with an increase in calling (see
also Schel et al. 2013a ). Furthermore, the production was often preceded by visual
monitoring of the audience with gaze alternations, and individuals were likely
to persist in emitting calls until all group members were safe from the predator.
As in the experiment by Crockford and colleagues ( 2012 ), chimps in this case
seemed to be capable of informing others with such reasoning as “I know something
that you don't know, and I know that this information is useful to you.” Chim-
panzees' vocal behavior seems to be, indeed, influenced by prosocial motivations
that are intentionally informing others of a danger.

5.5 Concluding Remarks and Future Directions

Considerations made so far seem to contradict some assumptions of Tomasello's
cooperative model, specifically the idea that chimpanzees have forms of only
individual intentionality and are not able to help others by informing. The results
of the studies discussed so far allow one to argue for continuity from apes to
humans by pointing at a kind of altruism of knowledge in apes. It is possible
to maintain, indeed, that the ability to communicate in a cooperative way is not
uniquely human but has its roots in the communicative abilities of chimpanzees to
help by offering information to others. These results are also particularly relevant
to debates about the evolution of a theory of mind and the relationship between
mental state attribution and language origins. It is not our intention to discuss the
long-standing dispute on the possession by apes of a theory of mind (e.g., Call and