Derived Relations Task With a Chimpanzee (video)

http://www.youtube.com/watch?v=NcgI-rxJOP8

Description: This is an old clip that's been used in a number of introductory RFT / derived relations slideshows. The video shows a chimpanzee having great difficulty in her efforts to solve a bidirectional task (after having learned a correspondence between different people and different letters on a keyboard, she has to «say» who goes to who by using a symbol meaning «to go to»).