The remarkable cognitive abilities of pigs create a compelling ethical argument for welfare standards commensurate with their intelligence.
Pig intelligence creates a proportionality challenge for ethics: if the capacity to suffer is partly a function of cognitive sophistication, and pigs have cognitive abilities comparable to or exceeding those of animals we treat with considerably greater concern, then the ethical framework governing pig farming requires examination. This is not an argument from pigs being identical to humans, but from pigs being sufficiently similar in the morally relevant respects — capacity for suffering, for positive and negative emotional states, for anticipation and memory — that dramatically different treatment requires justification. The industrial farming of hundreds of millions of pigs in conditions that prevent basic behavioural expression and cause chronic stress is difficult to justify when the cognitive and emotional sophistication of the subject is fully appreciated.