Pigs demonstrate emotional contagion — the ability to feel what others feel — with profound implications for group housing welfare in commercial farming.
Emotional contagion in pigs transforms how we think about group housing welfare. If pigs feel what their pen-mates feel, then a single distressed individual can create welfare harms across the entire group — and a single enriched, contented individual can spread positive states through the pen. This research argues strongly for management that prioritizes positive emotional states proactively rather than merely preventing negative states in individual animals. It also means that the welfare of each pig in commercial production affects the welfare of every pig they are housed with, creating a moral multiplier that makes individual welfare decisions collectively significant.