clipped from: news.bbc.co.uk Constructing a longer stick enabled the chimps to reach a food reward
Reporting in the Royal Society journal Proceedings B, scientists say this demonstrates what a "potent effect" social learning has in the primates.
"Those that had been shown the full demonstration, and had socially learned to make the longer tool, continued to make it even when the grape was so close that it was more awkward to use," said Dr Price.
"It could be that social learning is such a strong force for the chimps that they apply a blanket rule of 'go with what you've seen' (rather than work out what's most appropriate for the task)."