pan benisha, are you ready?. that's right. >> they connect words with photos. >> point to the bread. that's right. that's bread. >> a photo to a lexigram. >> perfect. >> and even more impressive is their ability to do the same tests in the opposite order. >> being able to do the inverse is often considered a uniquely human phenomenon because if you -- when animals learn an association, they typically learn it one direction, not bidirectional. >> even during the tests -- >> can you show me burrito? you're having trouble? you're having trouble finding burrito. pan benisha, come help konzi. >> there seem to be glimpses of human-like personalities. >> please come up here and help konzi and show him burrito. anderson needs to know where burrito is. where's burrito? can you find it? >> it's a secret. >> it's a secret. i see. >> some might say that was a mistake but to dr. savage-rumbaugh pan benisha is playing a joke. teasing both me and konzi. what are you trying to accomplish here? >> we're trying to look at the rel