Research into pig positive emotions has expanded significantly, documenting play behaviour, anticipation responses, and cognitive flexibility as indicators of genuine positive welfare states in pigs.
Pig welfare science has moved substantially beyond measuring the absence of suffering toward documenting genuine positive welfare states. Pigs experiencing good welfare show optimistic judgment bias, engage in play, and demonstrate anticipatory behaviour toward positive events. These are not merely anthropomorphic projections but measurable, validated indicators of positive emotional experience that welfare standards should actively promote.