All responses to death and loss thus far observed in apes concern individuals who were truly close (such as mother and offspring, or lifelong friends) and whose corpses the apes were able to see and touch. Mourning triggered by the mere mention of someone’s death requires a level of imagination and understanding of mortality that most of us don’t assume. It is precisely because of such inflated claims that the whole field of talking apes has fallen into ill repute over the years, and why no new projects of its kind are being initiated. Those that still do exist tend to resort to feel-good stories and publicity stunts to raise funds. There is too much of this going around, and too little hard-nosed science.
You won’t often hear me say something like this, but I consider us the only linguistic species. We honestly have no evidence for symbolic communication, equally rich and multifunctional as ours, outside our species. It seems to be our own magic well, something we are exceptionally good at. Other species are very capable of communicating inner processes, such as emotions and intentions, or coordinating actions and plans by means of nonverbal signals, but their communication is neither symbolized nor endlessly flexible like language. For one thing, it is almost entirely restricted to the here and now. A chimpanzee may detect another’s emotions in reaction to a particular ongoing situation, but cannot communicate even the simplest information about events displaced in space and time. If I have a black eye, I can explain to you how yesterday I walked into a bar with drunken people … and so on. A chimpanzee has no way, after the fact, to explain how an injury came about. Possibly, if his assailant happens to walk by and he barks and screams at him, others will be able to deduce the connection between his behavior and the injury—apes are smart enough to put cause and effect together—but this would work only in the other’s presence. If his assailant never walks by, there will be no such information transfer.
Countless theories have attempted to identify the benefits that language bestows upon our species and to explain why language may have arisen. In fact, an entire biennial international conference is devoted to exactly this topic, where speakers present more speculations and evolutionary scenarios than you can imagine.16 I myself take the rather simple view that the first and foremost advantage of language is to transmit information that transcends the here and now. There is great survival value in communication about things that are absent or events that have happened or are about to happen. You can let others know that there is a lion over the hill, or that your neighbors have picked up weapons. This is just one idea out of many, though, and it is true that modern languages are far too complex and elaborate for this limited purpose. They are sophisticated enough to express thoughts and feelings, convey knowledge, develop philosophies, and write poetry and fiction. What an incredibly rich capacity it is: one that seems entirely our own.
But as with so many larger human phenomena, once we break it down into smaller pieces, some of these pieces can be found elsewhere. It is a procedure I have applied myself in my popular books about primate politics, culture, even morality.17 Critical pieces such as power alliances (politics) and the spreading of habits (culture), as well as empathy and fairness (morality), are detectable outside our species. The same holds for capacities underlying language. Honeybees, for example, accurately signal distant nectar locations to the hive, and monkeys may utter calls in predictable sequences that resemble rudimentary syntax. The most intriguing parallel is perhaps referential signaling. Vervet monkeys on the plains of Kenya have distinct alarm calls for a leopard, eagle, or snake. These predator-specific calls constitute a life-saving communication system, because different dangers demand different responses. For example, the right response to a snake alarm is to stand upright in the tall grass and look around, which would be suicidal in case a leopard lurks in the grass.18 Instead of having special calls, some other monkey species combine the same calls in different ways under different circumstances.19
After the primate studies, the usual rippling has added birds to the list of referential signalers. Great tits, for example, have a unique call for snakes, which pose a grave threat as they slither into nests to swallow the young.20 But whereas these kinds of studies have helped raise the profile of animal communication, some serious doubts have been raised, too, and language parallels have been called a “red herring.”21 Animal calls do not necessarily mean what we think they mean: a critical part of how they function is how listeners interpret them.22 On top of this, it is good to keep in mind that most animals do not learn their calls the way humans learn words. They are simply born with them. However sophisticated natural animal communication may be, it lacks the symbolic quality and open-ended syntax that lends human language its infinite versatility.
Perhaps hand gestures offer a better parallel, since in the apes they are under voluntary control and often learned. Apes move and wave their hands all the time while communicating, and they have an impressive repertoire of specific gestures such as stretching out an open hand to beg for something, or moving a whole arm over another as a sign of dominance.23 We share this behavior with them and only them: monkeys have virtually no such gestures.24 The manual signals of apes are intentional, highly flexible, and used to refine the message of communication. When a chimp holds out his hand to a friend who is eating, he is asking for a share, but when the same chimp is under attack and holds out his hand to a bystander, he is asking for protection. He may even point out his opponent by making angry slapping gestures in his direction. But although gestures are more context-dependent than other signals and greatly enrich communication, comparisons with human language remain a stretch.