Research into pig emotional states has revealed a rich inner life including positive emotions like play and anticipation. This evidence strengthens the welfare case for enriching pig environments and reducing negative experiences.
The emotional lives of pigs have been illuminated by a decade of innovative welfare science that has moved beyond documenting negative states to demonstrating genuine positive emotional experience. Judgment bias testing — presenting animals with ambiguous stimuli after inducing positive or negative mood states — shows that pigs in enriched, positive welfare conditions make systematically more optimistic responses, just as humans in positive emotional states are more optimistic. This methodology, developed from clinical psychology, provides behavioral evidence for subjective emotional states that would otherwise be inferred only indirectly. The practical implications are significant: pigs in positive emotional states are not just in better welfare — they are also healthier, faster-growing, and easier to manage. The emotional state of pigs is a product of their environment: enrichment, social stability, positive human-animal relationships, and freedom from chronic pain and fear all contribute to positive affect. Farms that invest in these conditions are simultaneously improving welfare and production outcomes, an alignment that should make emotional welfare a commercial priority as well as an ethical one.