However, it’s difficult in the wild to complete the behavioural experiments that could test whether these are truly socially learned traditions, so we have pioneered such experiments with captive apes. Our exhibit illustrates a study in which a single chimpanzee in each of two groups was shown a different method to deal with an artificial foraging task (the ‘pan-pipes’) then reunited with her group.
We have shown that several alternative techniques like this can spread in different groups and become local traditions . Chimpanzees preferentially copy high status individuals. 
 Whiten. A. et al. Cultures in chimpanzees. Nature, 399, 682-6
 Whiten, A., et al. (2005). Conformity to cultural norms of tool use in chimpanzees. Nature, 437, 737-740.
 Whiten, A. et al. (2007) Transmission of multiple traditions within and between chimpanzee groups. Current Biology, 17, 1038-1043.