Skeptics point out that apes certainly don’t use symbols or words to talk about the weather or their children; they can refer to something other than a reward, but only if a reward is waiting at the other end. (It would be interesting to observe what would happen to symbol-trained apes if their trainers stopped rewarding them. Would they continue to use the symbols?) The important point, I think, is that words don’t seem to be intrinsically part of most apes’ affective niche, as they are for typical human babies. To apes, words alone are not worth learning.
