You can tell a bonobo from a chimpanzee because the bonobo has red lips, hair that parts down the middle with stylish tufts standing out, and lacks the grizzled white beard of a chimp. Here’s Kanzi, 26, conversing with Professor Sue Savage-Rumbaugh. Though he still can’t create one, Kanzi can understand an unfamiliar long sentence about as well as a two-year-old child.

Kanzi’s the head of an extended family of eight bonobos at the new Great Ape Trust of Iowa. It draws scientists from around the world to Des Moines because the apes there have attained many elementary language abilities. While human preschoolers absorb nine new words a day, apes aren’t so naturally acquisitive. But they do value the social interaction with their teachers and so they learn hundreds of words.

I’ve been visiting Kanzi since he was nine. If I need to put a face to what human intellect was like six million years ago, Kanzi usually comes to mind. His snap emotional judgments and elementary cooperation strategies are probably much like ours. But he’s not likely to invent an alternative crop rotation and discuss its merits. He may experience a “eureka moment” when finding a hidden treat, but he’s unlikely to become addicted to finding each hidden pattern in a crossword puzzle.

Alas, the wild populations of the great apes are crashing everywhere because of logging and hunting. There are only 130 bonobos in zoos and research centers around the world and eight are now in Iowa.