Cognitive bias testing reveals the emotional state of pigs, with optimistic responses indicating good welfare and pessimistic responses indicating chronic stress.
Cognitive bias testing represents a breakthrough in farm animal welfare assessment because it measures the animal's subjective emotional state directly rather than inferring it from behaviour. A pig in chronic stress approaches life expecting negative outcomes - a pessimistic cognitive bias. This has profound welfare implications: the test demonstrates that welfare is not merely about preventing specific problems but about creating conditions where animals anticipate positive experiences. This is the science behind positive welfare.