Pigs are cognitively complex animals whose intelligence rivals that of dogs and young children. This cognitive capacity makes their welfare in farming systems a significant ethical concern.
The cognitive complexity of pigs means that welfare failures cause both physical and psychological suffering. Social isolation causes measurable depression in pigs, demonstrated through pessimistic cognitive bias in judgment tasks. Confinement prevents natural rooting, exploring, and socializing behaviors that pigs are highly motivated to perform. The frustration of these motivations in conventional farming systems causes chronic negative emotional states. Environmental enrichment studies consistently demonstrate that pigs given more complex environments show positive indicators of welfare.