▁chain ▁that ▁delivered ▁food ▁to ▁themselves ▁if ▁doing ▁so ▁also ▁caused ▁a ▁companion ▁to ▁receive ▁an ▁electric ▁shock . ▁This ▁in hib ition ▁of ▁hur ting ▁another ▁cons pec ific ▁was ▁more ▁pron ounced ▁between ▁familiar ▁than ▁un famil iar ▁mac a ques , ▁a ▁finding ▁similar ▁to ▁that ▁of ▁em path y ▁in ▁humans . ▁ ▁Furthermore , ▁there ▁has ▁been ▁research ▁on ▁cons olation ▁behavior ▁in ▁ch imp anze es . ▁De ▁W aal ▁and ▁A ure li ▁found ▁that ▁third - party ▁contacts ▁attempt ▁to ▁rel ieve ▁the ▁dist ress ▁of ▁contact ▁participants ▁by ▁cons ol ing ▁( e . g . ▁making ▁contact , ▁emb rac ing , ▁gro oming ) ▁recip ients ▁of ▁ag gression , ▁especially ▁those ▁that ▁have ▁experienced ▁more ▁inten se ▁ag gression . ▁Research ers ▁were ▁unable ▁to ▁rep licate ▁these ▁results ▁using ▁the ▁same ▁observation ▁protocol ▁in ▁studies ▁of ▁mon keys , ▁demonstr ating ▁a ▁possible ▁difference ▁in ▁em path y ▁between ▁mon keys ▁and ▁ap es . ▁ ▁Other ▁studies ▁have ▁exam ined ▁emot ional ▁processing ▁in ▁the ▁great ▁ap es . ▁Specifically , ▁ch imp anze es ▁were ▁shown ▁video ▁cli ps ▁of ▁em otion ally ▁charged ▁scenes , ▁such ▁as ▁a ▁det ested ▁veter inary ▁procedure ▁or ▁a ▁favorite ▁food , ▁and ▁then ▁were ▁required ▁to ▁match ▁these ▁scenes ▁with ▁one ▁of ▁two ▁species - specific ▁fa cial ▁expressions : ▁" h appy " ▁( a ▁play - face ) ▁or ▁" s ad " ▁( a ▁teeth - bar