[danielf]

There's a bit more here:

http://www.nature.com/news/2005/0508...050815-12.html

Once trained, the animals were returned to their social groups. As expected, most of the peers used the same technique as the one they observed from the trained chimp. Animals that didn't have an example to follow simply couldn't get the grape out.

Some animals did spontaneously switch from one behaviour to the other when they tried to retrieve the grape, figuring out the alternative method themselves. But two months later, most animals had switched back to the majority behaviour in their group.

Whiten points out that even animals who initially poked - a behavior more natural for chimpanzees than lifting - reverted to lifting eventually. "This is an even stronger social learning tendency than we went out to test for," Whiten says. "It's very exciting. We were surprised."

They were returned to their separate groups. I also think that the conclusions are a little far-fetched. I'm not sure if this shows a 'desire to conform'. Interesting stuff though...