I ' m ▁sorry ." ▁If ▁he ▁said ▁" W anna ▁ban ana ", ▁but ▁was ▁offered ▁a ▁nut ▁instead , ▁he ▁st ared ▁in ▁silence , ▁asked ▁for ▁the ▁ban ana ▁again , ▁or ▁took ▁the ▁nut ▁and ▁threw ▁it ▁at ▁the ▁research er ▁or ▁otherwise ▁displayed ▁anno y ance , ▁before ▁request ing ▁the ▁item ▁again . ▁When ▁asked ▁questions ▁in ▁the ▁context ▁of ▁research ▁testing , ▁he ▁gave ▁the ▁correct ▁answer ▁approximately ▁ 8 0 ▁percent ▁of ▁the ▁time . ▁ ▁Once , ▁Alex ▁was ▁given ▁several ▁different ▁colored ▁blocks ▁( two ▁red , ▁three ▁blue , ▁and ▁four ▁green — similar ▁to ▁the ▁picture ▁above ). ▁Pe pper berg ▁asked ▁him , ▁" What ▁color ▁three ?" ▁expecting ▁him ▁to ▁say ▁blue . ▁However , ▁as ▁Alex ▁had ▁been ▁asked ▁this ▁question ▁before , ▁he ▁seemed ▁to ▁have ▁become ▁b ored . ▁He ▁answered ▁" five !" ▁This ▁kept ▁occurr ing ▁until ▁Pe pper berg ▁said ▁" F ine , ▁what ▁color ▁five ?" ▁Alex ▁replied ▁" none ". ▁This ▁was ▁said ▁to ▁suggest ▁that ▁par ro ts , ▁like ▁humans , ▁get ▁b ored . ▁Sometimes , ▁Alex ▁answered ▁the ▁questions ▁incorrectly , ▁despite ▁knowing ▁the ▁correct ▁answer . ▁ ▁Pre lim inary ▁research ▁also ▁seems ▁to ▁indicate ▁that ▁Alex ▁could ▁carry ▁over ▁the ▁concept ▁of ▁four ▁blue ▁balls ▁of ▁w ool ▁on ▁a ▁t ray ▁to ▁four ▁notes ▁from ▁a ▁piano . ▁Pe pper berg ▁was ▁also ▁training ▁him ▁to ▁recognize ▁" 4 " ▁as ▁" four