Pigs are among the most cognitively sophisticated farm animals. Understanding their intelligence has profound implications for how we design their environments and assess their welfare.
The cognitive sophistication of pigs makes their routine housing in barren, restrictive environments particularly troubling from a welfare perspective. Pigs in enriched environments are more optimistic, less aggressive, and show better immune function than those in barren systems. Cognitive and affective research on pigs is informing welfare standards: the European Union and many other jurisdictions now require environmental enrichment for pigs in commercial settings. Effective enrichment must be novel, manipulable, and provide genuine challenge — straw, rooting materials, and objects to investigate meet these criteria better than simple fixed toys. Understanding pigs as intelligent social animals changes the ethical weight of decisions about their management.