Pigs are among the most cognitively complex farm animals, with intelligence comparable to dogs. Understanding pig cognition has significant implications for how their welfare needs should be met.
The cognitive complexity of pigs fundamentally changes the ethical calculus of intensive pig farming. Intelligent animals require not just physical welfare provision but cognitive engagement and environmental complexity. Pigs deprived of cognitive stimulation in barren environments develop depressive-like states measurable through cognitive bias tests. They show pessimistic responses to ambiguous stimuli, reduced motivation to explore and increased passivity. The contrast between pig cognitive capacity and the environments most are raised in is stark. Providing rooting materials, foraging opportunities, novel objects and social stability costs relatively little but significantly improves the cognitive welfare of animals capable of experiencing what amounts to psychological suffering from intellectual deprivation.