Cognitive bias tests provide a powerful scientific tool for measuring the subjective emotional states of animals — revealing whether they are experiencing something like optimism or pessimism in response to their conditions.
Cognitive bias testing represents a landmark methodological advance in animal welfare science. By measuring whether animals expect good or bad outcomes from ambiguous situations, researchers can assess the subjective emotional state of animals across species and conditions. This provides objective evidence for what many people intuitively sense — animals in better conditions feel better — and gives regulators and farmers a scientific basis for welfare improvement requirements.