How Monkeys See the World tries to answer one of those
questions that has always intrigued people - how much do
animals understand about the world? It concentrates on vervet
monkeys (the authors' own fieldwork was done on groups of
vervet monkeys in Amboseli national park, Kenya), but it also
draws on studies of other primate species - in the wild, in
captivity, and in laboratory experiments - and comparisons are
made throughout with non-primate species.
Since the questions being asked - Are monkeys self-conscious?
Do they have emotions? - are not only difficult to answer but
use terms which are themselves contentious, methodological
issues are critical. Cheney and Seyfarth eschew an explicitly
behaviourist approach, but are very careful when interpreting
anecdotal evidence of monkey behaviour. They are also
conservative in their claims for monkey intentionality, with the
result that what they do claim seems convincing.
How Monkeys See the World begins with a study of vervet
monkeys - their ecology, social hierarchy, behaviour, and
vocalisations. This is then used to look more generally at such
behaviours as deception and attribution, and the ways these can
provide insights into monkeys' mental processes. The
conclusion the authors draw is that monkeys have at least first
order intentionality - they have emotions, mental states, and so
forth - and a very good understanding of monkey behaviour.
Vervet vocalisations do have meaning and form a rudimentary
"language". However there is no clear evidence that monkeys
know that other monkeys have mental states, or that they have
self-awareness. The evidence for this kind of second-order
intentionality is most convincing (but still equivocal) for
chimpanzees, and there seem to be qualitative differences
between monkeys and apes.
Also, intelligence in primates is domain specific - restricted to
certain areas of application and not generally accessible. Social
problems are often more adeptly solved than non-social ones,
and it seems likely that a major selective force acting in the
evolution of human intelligence was the need to understand and
organise social interactions. The ideas presented have
interesting consequences for the origins of human language.
How Monkeys See the World is a very very interesting book,
and anyone interested in cognitive psychology, human
evolution, linguistics or ethology (or even just monkeys!) will
want to read it. A minor complaint is that all references to
evolution seem to assume a fairly naive adaptionist viewpoint
(but then maybe I've just been reading too much Stephen Jay
Gould).