As it was told in one of Karl Pilkington's semi-legendary, semi-gibberish "Monkey News" segments, a zookeeper who once brought home a chimp from work because the latter was "looking a bit fed up" came eventually to discover his new houseguest had been having it away with his missus. Ricky Gervais, wisely, was having none of it, but this new documentary from James Marsh (Man on Wire) - with its essential ingredients of domesticity, human oversight and animal behaviour - suggests Pilkington's tale, or a story like it, might just have some substance yet.
In 1973, Herb Terrace, a professor at Columbia University, assigned a chimp called Nim to psychology postgraduate (and Herb's former lover) Stephanie LaFarge, intending her to raise him as she would any human child. Nim was duly taken in, put in nappies, taught rudimentary sign language, and even breastfed when the occasion called for it; as the years passed, he would, at social events, be passed the whisky bottle and the joint. (Marsh has unearthed a damningly funny photograph of the chimp surrounded by a haze of pot smoke.) "It was the 70s," shrugs LaFarge's daughter Jenny, by way of a defence of her elders' methods.
The project had similarly hazy guidelines, but a particular law of the jungle - that male chimps are hotwired to challenge (and eventually overcome) those other males surrounding them - began to hold sway. The primal urge did for LaFarge's husband Wer, a poet who objected to Nim's tendency to tear all his books to shreds, and the test subject would eventually be spirited away to be taught advanced linguistics by Terrace himself, the real alpha of this group, with the aide of another pretty undergraduate. We quickly grasp that if Nim was raised as a child, it was as the child of a broken household - with a series of mothers who found themselves at the mercy of Terrace's bluff, controlling "father". Inevitable, then, that the story should effectively develop as a tug-of-love custody battle, one that can only conclude with a courtroom battle. There are points where you half-expect Stockard Channing to crop up.
Some of Marsh's archive footage suggests this project wasn't a dead loss. We see Nim happily signing away with his keepers, interacting with both man and fellow beast at an especially advanced level. ("I had a conversation with another species!," is the excited response of one handler.) Yet these small evolutionary steps forward came at a considerable psychic cost to Nim himself, who ended up clingy and in constant need of attention. After sinking his teeth through the cheek of one of Terrace's staff, he was removed to captivity - a fate common amongst those from broken homes, we note - where, like a mummy's boy in the prison yard, he suffered: medical testing, depression, dog murder and a final attempt at matricide all follow.
The story is maddening, tragic and compulsive enough in its own right not to need additional whistles and bells, and Marsh duly strikes a skilful balance between the personalities involved, the narrative and his own technique; the handling becomes particularly effective over the closing stretch, as the key players speak - movingly, in most cases; somewhat evasively, in the case of Herb Terrace, who launched a whole academic career off the back of the Nim data - about the their part in what happened to their pupil, their charge, their boy.
There's little of the mystery or awe one found in Marsh's previous Wisconsin Death Trip or Man on Wire - it's the kind of anecdote even Karl Pilkington could get his round head around - and I'm not so sure what we're supposed to take away, other than the sense of having borne witness to a good story well told. Don't hand your chimp to 1970s scientists? Are we as humans less evolved than we think? (These would seem respectively moot and obvious avenues for Marsh to be exploring.) Well told it is, though - and it may be the only film you'll see all year to feature (frankly priceless) footage of a chimp attempting to hump a cat.
Project Nim opens in selected cinemas from tomorrow.