An interesting data point for putting a ceiling on an animal's ability to produce language is this lecture discussing various animals (mostly apes) learning American Sign Language (starting at ~1h18m).
My take-away is that some chimps may be capable of remembering and reproducing words, but not string them together meaningfully: word order is effectively random, length of sentence does not correlate with information content. The lecture discusses (at about 1:34:56) the turning point of the field when H. Terrace was unable to reproduce the generally optimist... (read more)
An interesting data point for putting a ceiling on an animal's ability to produce language is this lecture discussing various animals (mostly apes) learning American Sign Language (starting at ~1h18m).
My take-away is that some chimps may be capable of remembering and reproducing words, but not string them together meaningfully: word order is effectively random, length of sentence does not correlate with information content. The lecture discusses (at about 1:34:56) the turning point of the field when H. Terrace was unable to reproduce the generally optimist... (read more)