Reported Speech

From an exchange with linguist Noam Chomsky:

Question: In reported speech, what is the approximate human limit to understanding embedded phrases? For example, "John asked Mary to tell Susan that Mark asked Alex to tell Jill ..." Or, for comparison, "He asked her to tell him that he asked her to tell her ..." Moreover, what are the reasons for the limitation? My initial guess is short term memory, but I imagine there is a lot more going on behind the scenes. When I tested it with both NS and NNS, one of the first effects was that people started interchanging pronouns. I'm not sure what was happening in the mind.

Answer: Those are not embedded. Recursion is often confused with embedding. Sentences of the form you mention can be understood up to the limits of patience. They are typically reformulated prosodically in speech, like the famous "this is the cat that ate the mouse.....the house that Jack built."

Truly embedded sentences, like "if [the man [who Bill saw] is smart] then...." can be understood up to about 7 embeddings, as expected: that's the cross-specific limit on short-term memory. Self-embedding, like a relative clause within a relative clause, breaks down in speech at about 3. There's discussion of this in a paper of George Miller's and mine in Luce, Bush, Galanter eds., Handbook of Mathematical Psychology, about 1964.

An example of 3: The man who the boy who you met saw likes Mary.
Try: The woman who the man who the boy who you met saw likes just left.