Two years after taking home an Oscar for the tightrope documentary "Man on Wire," British director James Marsh has come to Sundance with a heartbreaking tale about a chimp raised to be human.
"Project Nim" tells the story of a 1970s US experiment in which a chimpanzee was raised as a human child and taught sign language in the hope of proving that language was not limited to humanity.
"The film reflects the intellectual climate of the time, the whole debate about nature and nurture," Marsh told AFP about the latest documentary. "At that time, nurture was very very powerful, if not the dominant influence, on the human children."
Marsh has previously won at Sundance with "Man On Wire," a documentary about a 1974 stunt in which Frenchman Philippe Petit walked a tightrope between the Twin Towers before being arrested by New York police.
In "Project Nim" he looks at a project dreamed up by Columbia University psychologist Herbert Terrace and carried out on Nim Chimpsky, a chimp named for famed linguist Noam Chomsky, who has argued language is uniquely human.
Alternating between previously unpublished footage and interviews with participants in the experiment, the film shows how Nim initially connects with his family before his animal nature gradually takes over.
"What surprised me the most is the depth of the feelings and the guilt that the people felt still now," Marsh said.
"Their emotional connection with the chimp was very, very strong and it all came out as we were talking about it."
The adoptive mothers in the film seem to have never recovered from their separation from Nim and say they still bear the burden of his eventual caging in a primate research center, far from the humans who raised him.
When the baby chimp is given to the first of a series of adoptive mothers, "it's physical and sensual," Marsh said.
"If you give a kind of baby creature to a human mother - that's what happened here, it's a very sensual relationship... There is some kind of love affair between the woman and the chimp."
As the chimp grows older and more aggressive and is passed on to other teachers, "They keep nurturing him... he beats her, he hurts her and she carries on. It's heroic, really."
The scientific value of the four-year study remains open to debate. Terrace wrote in 1979 that there was little evidence the chimp had learned language, while other scientists have faulted his methods.
For Marsh, the story is less about Nim than about those around him who, at least initially, are possessed of a seemingly boundless optimism that they can control him and mold him in their own image.
"I wanted to try to see how the human behavior is influenced by the chimp... We think that we can find out everything, control everything and of course, with a chimp you can't."
The bonds that form between Nim and the different people who care for him provide a touching counterpoint to the experiment itself.
"For me, it's more perverse to put a chimp in a classroom, like a public schoolboy, than to give him a joint, for example," Marsh said, referring to one of the funnier scenes of the often humorous film.
Marsh hopes that viewers of the film at this year's Sundance independent film festival, held in the western US state of Utah, will relate to both the misguided trainers and the unfortunate primate.
"We can see something of ourselves here. In a way, it's kind of scary. We humans are a species capable of enormous amounts of violence and aggression. We like to get drunk, to take drugs, and chimps love that too."Reuse content