Babel's Dawn

Unique Properties of the Human Mind

Cats that look like humans and humans that look like cats are unknown to nature, but commonplaces of speech. How can that be?

The April issue of the Journal of Anatomy is devoted to review articles on the evolution of humans. The result is as handy as an up-to-date textbook. What’s more, all the articles appear to be free. So I suggest readers jump to the journal’s table of contents and start downloading those PDFs. The article most directly concerned with issues on this blog is “A natural history of the human mind: tracing evolutionary changes in brain and cognition” by a team from The George Washington University’s Mind, Brain and Evolution Center (Chet C. Sherwood, Francys Subiaul, and Tadeusz W. Zawidzki). The most useful part of the article for readers of this blog is probably its listings of mental traits that humans share with apes and traits that are unique to humans. Listening, sharing information, and expressing a boundless imagination all rest on the unique traits.

BioScience Article

An article I wrote about the Evolang conference in Barcelona is available for free online at the BioScience site here. BioScience is the magazine of the American Institute of Biological Sciences.

Autism and Joint Attention

Joint Attention is often thought to require catching another's eye and a willingness to look in the eye.

It has long seemed to me that if we understood the origins of speech, we would better understand what it is that sets humanity apart from the rest of the animal kingdom. Many people come at the issue from the other end. They claim to identify what it is that sets humanity apart, and then try to relate their conclusion to speech. The proposed X factor might be rational thought, recursive syntax, having a theory of mind, symbolic thinking, tool using, etc. Sometimes the proposed X turns out to exist elsewhere in the primate world, but even when the assumption stands, the approach turns the problem of speech origins into a two step affair:

1. Explain the origins of X, and,
2. given X, explain the origins of speech.

I have tried to simplify the problem by coming at from the other end. Learn something about the origins of speech and see what X emerges. After last week’s post (here) it seems to me that an X may have emerged.

Speech Includes Gesture

Some gestures stay in the mind as sharply as the most memorable phrase.

Simone Pika has published a useful review of ape gestures in the First Language journal, “Gestures of apes and pre-linguistic human children: Similar or different?” (abstract here). I don’t suppose it will bowl anyone over with its finding that while both apes and children can make imperative gestures (e.g., give me food) human children, but not apes, also make “gestures for declarative purposes to direct the attention of others to some third entity, simply for the sake of sharing interest in it or commenting on it” [p. 131]. But when all the different sorts of ape gestures are drawn together it is quite evident that the really peculiar aspect of speech is the presence of what this blog calls the speech triangle, and what Pika calls triadic form. That is, humans are peculiar in having a speaker, a listener, and an outside topic.

Dyadic gestures—actions used to attract attention to the actor—are common enough among apes, but informative triads among apes in the wild are almost unknown. (The one exception: a free bonobo once was observed probably pointing out human observers hiding in the bushes.) Pika says a little ambiguously, “It is therefore quite puzzling why only human beings comment on outside entities simply to share experiences.” I would put it a little differently. It’s quite puzzling how we came to comment on outside entities when no other animal seems to share the need. Once we can give a solid explanation for that puzzle, we will have come a long way in understanding why humans are different.