Can monkeys think?
Vervet monkeys use different warning sounds depending on what sort of predator is around. And some ingenious recent research has confirmed that these monkeys really do assign a separate meaning to the individual sounds.
However, researchers point out that this does not mean that their sounds have the significance of human words, because human communication means 'attributing mental states to others'—that is, knowing that others know, or having a theory of mind.
In fact, further experiments have shown that these monkeys lack such an ability. The researchers found that 'monkeys and perhaps even apes cannot communicate with the intent to modify the mental states of others [as humans do] because, apparently, they do not recognise that such mental states exist'.
December 1992, pp. 78-84.
Chimps are capable of grieving at the death of another, but no chimp ever recognises that its neighbour is grieving and seeks to comfort it. In spite of the impression given by the popular media, the gulf between human and animal consciousness, thought and feeling is vast and unbridgeable (Genesis 1:27).