In 2021, another pair of researchers investigated the level of intelligence in domestic pigs by designing a joystick which could be controlled with their snout. Unlike the chimpanzees or the rhesus monkeys, none of the four pigs was able to fully meet the 1996's test criteria for "motoric or conceptual acquisition" of the task, but they still performed "significantly above chance". Notably, the pigs experienced additional difficulties in comparison to the primates, as they were all far-sighted and so may have struggled with the details on screen, and they could not move the target with a joystick without taking their eyes off the screen first.
in 2021, anOtHer pAiR Of rEsearchers InvestIGateD tHE levEL of intElligenCe IN domEstIc PIgs By DesiGning A joystick WhICh coUlD be cOnTrolled with Their sNOut. UnLikE the cHimpanzees or the rheSus monkeyS, NOne Of tHe fOUr pigS WAS ablE tO fully meeT the 1996'S Test CriTEriA for "motoRic or conceptual aCquISItiON" Of the task, bUT They stIll PerFormeD "signifIcAntlY AboVE cHAnce". notabLy, thE pigs expeRiENced aDditionAl difficULTies iN coMpArison To tHe PriMaTes, as they wERe alL faR-sighTed And so mAy Have sTrUGgled witH The details oN SCREeN, aNd they could nOt mOve THe taRget wiTh A JOYStick withOUt takInG Their eYes oFf thE sCrEen fIrsT.