Some people believe that pigs are smarter than dogs, but there are no scientific studies to prove this theory beyond mere speculation. The world of pigs and dogs are so completely different that it is difficult to accurately measure the intelligence of one species against another.
Pigs and dogs are considered highly intelligent animals by human standards, and studies have borne this view out by demonstrating that pigs are fast learners capable of performing tasks while responding to visual cues. In one study, pigs were taught how to move a video game cursor with their snouts.
Pigs may also act deceptively by outsmarting other pigs, as a bucket test showed. In this exercise, smaller pigs figured out how to act evasively to prevent larger pigs following them to food buckets. A mirror test proved that pigs understand self-awareness. In this test, a group of pigs were introduced to mirrors and became familiar with seeing their reflections. The next day, the pigs saw food reflected in the mirrors and figured out where to find it, passing the self-awareness test.
Dogs have also been tested for intelligence and have shown that they can distinguish between photos of dogs and scenic landscapes, so dogs are capable of understanding some nonverbal cues as well.