Those wild chimps have been using twigs as dolls for... ever, in all likelihood. Those data were collected over the course of almost two decades, but here's something which is a new(ish) development in Chimp "tool" use, and potentially asks some intriguing questions about the origins of culture.
Cultured Chimps Invent and Share Back-Scratching Tool
"I would sometimes spend days trying to find the chimps and then they might travel through everything from muddy swamps and thick undergrowth to colonies of army ants before there'd be a good chance to film them," said researcher Catherine Hobaiter, a primatologist at the University of St. Andrews in Scotland. "But then, when you do get to observe them in their natural habitat, it's an incredibly rewarding experience, and you completely forget about the fact you're sitting in the mud with ants in your socks!"
One chimpanzee there was named Tinka, a roughly 50-year-old male who had near-total paralysis in both hands. Until recently, Sonso chimpanzees would encounter large numbers of snares intended for bush pigs and kinds of antelopes known as duiker, leading one-in-three adult chimps in the community to have permanent disabilities.
To compensate for his paralysis, Tinka invented a new way to groom himself using a liana, or woody vine. Imagine using a towel on your back, except in this case, rather than moving the towel, Tinka held the liana taut with his feet and moved his body against it.
Yeah, so the article is from August. I've had a bit of a backlog. I'll link to directly to the video, though. You ought to watch it so you can see how unimpressive the actual behavior appears to be. That's not really the point though - its about the fact that this old paralyzed dude invented the behavior from scratch (oh I'm so clever), and then the chimps in community picked up a completely novel behavior by copying the actions of another.
How cultural elements are transferred and absorbed is kind of a big deal (at least to me), since we know so little about it, and in humans, we don't have many effective ways to design ethologically sound experiments. Plus, creating proper controls is a bitch. The chimps in this study were entirely wild, however, and though this study was purely observational, if chimps are capable of cultural transmission, it might open up new avenues for experimentation along these lines.