Most people know swine only as its domestic form (Sus scrofa domesticus) or as wild boar (Sus scrofa scrofa). Relatively little attention goes to the rest of a total of up to 18 species in the Suidae family. The same also applies to behavioral research: although members of the family of Suidae are distributed all over the Old World, ranging from Asia to Europe and Africa, most studies focusing on their behavior and cognition are conducted on domestic swine.

In public perception, swine do not have the best reputation regarding their cognitive capacity, and they are often perceived as dumb as well as voracious and dirty. In contrast, fairy tales and fables, such as the Three Little Pigs or Animal Farm, depict swine as smart and intelligent enough to outwit potential predators or liberate themselves from the tyranny of their human masters.

In real life, swine have successfully adapted to various climatic and vegetation zones and exhibit a high foraging flexibility that is reflected in their omnivorous dietary spectrum. Their mixed diet makes it necessary for them to recall food distributed in patches that vary in spatial location but also in time. Swine are very social animals, forming long-lasting family bonds, and exhibit fission-fusion dynamics. All in all, these ecological and social circumstances require high brain processing power.

First investigations on the learning abilities of domestic swine date back to more than 100 years ago, and operant learning in swine was intensively examined in the late 1960s and 1970s (e.g., Wieckert and Barr 1966). Starting 20 years ago, questions on swine’s cognitive capacities gained increased attention, and research began to examine their ability to remember food patches, solve problems when dealing with hard-to-access food, and recognize and discriminate between familiar and unfamiliar individuals (e.g., Gieling et al. 2011). The increased interest in their cognitive abilities is, on one hand, based on the fact that swine are physiologically more similar to humans than rodents are; therefore, domestic swine are increasingly used as a model organism in neuroscience and biobehavioral research. On the other hand, insights into the cognitive capacities of swine can be used to improve the welfare of this intensively kept farm animal by designing methods to enrich their environment (Puppe et al. 2007).

Research on swine cognition has mostly been conducted on domestic swine, but given that all swine species are social and occupy a similar ecological niche, we can assume that conclusions drawn on domestic swine will likely apply to other species of swine as well.