Animal welfare science has transformed our understanding of how animals experience the world. By 2026, converging evidence from neuroscience, behavioural biology, and veterinary research has established that a far wider range of animals than previously recognised are capable of suffering, pleasure, and complex emotional states.
Animal welfare science has moved from a focus purely on preventing negative states to a dual framework that also seeks to promote positive experiences. The Five Domains model explicitly includes 'mental state' as a domain, recognising that animals have subjective inner lives that welfare interventions must address. Cognitive bias testing — assessing whether animals interpret ambiguous stimuli optimistically or pessimistically — provides a window into emotional state that goes beyond behavioural observation. Play behaviour, voluntary interaction with enrichment, and affiliative social contact are positive welfare indicators increasingly incorporated into farm assurance audits and zoo accreditation standards. By 2026, the scientific consensus that vertebrates and many invertebrates are sentient is robust, and the moral weight of animal welfare in policy is increasing accordingly.