Pigs are among the most cognitively sophisticated animals farmed for food. Research over the past two decades has documented problem-solving, emotional contagion, self-awareness, and complex social cognition in pigs — findings with significant implications for how we evaluate their welfare needs.
The cognitive research on pigs creates an uncomfortable gap between what we know about their inner lives and how we treat them. Pigs that can solve puzzles, empathise with distressed companions, and potentially recognise themselves in mirrors are confined in systems that deny them movement, social choice, and environmental complexity. The emotional contagion finding is particularly welfare-significant: in crowded, stressed pig populations, negative affect spreads through the group, meaning individual welfare and group welfare are inseparable. Conversely, positive welfare interventions — enrichment, appropriate social grouping, positive human-animal interactions — can create positive affective states that spread through groups. The welfare science here is mature enough to demand policy change; the gap is political and economic will.