Pigs are cognitively comparable to dogs and demonstrate sophisticated learning, play, and emotional responses. These findings have profound implications for how we assess and improve pig welfare in farming systems.
Pig cognition research has fundamentally changed the scientific understanding of what pigs experience. They are not simple stimulus-response machines but cognitively rich animals with individual personalities, the ability to learn complex tasks, and emotional lives that include optimism, pessimism, empathy, and playfulness. In good welfare conditions, pigs play — they run, jump, and engage in social games. In poor conditions, play disappears and is replaced by stereotypic behaviour and redirected aggression. Using cognitive bias tests — assessing whether pigs interpret ambiguous stimuli optimistically or pessimistically — researchers can now infer emotional state in ways that provide objective welfare evidence. This research creates a scientific foundation for arguing that the barren intensive systems in which most pigs live are incompatible with their cognitive and emotional needs.