Research into positive emotional states in pigs has advanced significantly, demonstrating that pigs experience not just negative states like fear and frustration, but also positive states including joy, curiosity, and anticipation.
Understanding that pigs experience positive emotions is transformative for welfare science and practice. A welfare science focused only on reducing suffering misses half the ethical picture — animals have capacities for enjoyment, play, and curiosity that are intrinsically valuable. Providing pigs with environments that enable positive emotions — enrichment, social play, foraging — is not merely preventing harm but actively promoting welfare. This shift from deficit-reduction to positive promotion represents a maturing of the field.