Study

Comprehension of sentences by bottlenosed dolphins

Herman, Louis M.; Richards, Douglas G.; Wolz, James P.

Cognition, 1984

Peer-reviewedcontrolled laboratory experimentcaptive

What they did

Two dolphins were taught artificial languages — one gestural, one acoustic — with a vocabulary of objects, actions and modifiers and a consistent word order. They were then tested on novel sentences never previously encountered, including sentences whose meaning depended entirely on word order.

Studied in: Tursiops truncatus
Sample size: 2 dolphins trained on artificial gestural and acoustic languages

What they found

Both dolphins responded correctly to novel sentences, including reversible ones where the same words in a different order specify a different action, indicating sensitivity to syntactic structure rather than to word lists.

What it means

The authors' reading, and ours. Where they differ, that difference is the point.

How the authors put it

Dolphins can extract meaning from the order of symbols, demonstrating comprehension of a rudimentary syntax.

How NatureHQ reads it

The distinction that matters here is comprehension versus production. These dolphins understood structured instructions; they did not produce structured utterances, and nothing in their natural communication has been shown to have this property. It is a result about what a dolphin brain can be taught to parse, which is a genuine and interesting question, and not evidence that dolphins have a language of their own.

Limitations

Two animals, extensively trained over years by the same team.
Comprehension of a taught artificial system says nothing directly about natural communication.
Cueing by trainers is difficult to exclude entirely in this design, though controls were used.