chimpanzees sorrowful countenance hints at its underlying feelings of sadness and dejection

chimpanzees sorrowful countenance hints underlying feelings sadness dejection primates emotions expressions facial features nonhuman animals sorrow gloom misery despair melancholy unhappiness glumness dejectedness desolation despondency forlornness woefulness heartache woe mournfulness dolor downheartedness gloominess blue despondence wretchedness plaintiveness moroseness cheerlessness moodiness grief