Research into animal emotions has accelerated dramatically, with neurobiological and behavioral evidence now demonstrating that animals experience emotions with welfare implications.
The science of animal emotions has transformed from a taboo subject to a mainstream research field. Affective neuroscience has identified homologous brain systems across vertebrates including the limbic system, amygdala, and reward circuits that generate emotions. Evidence for primary emotions including fear, anger, joy, curiosity, sadness, care, and play behaviors has been demonstrated across diverse species. Social emotions including empathy and grief have been documented in elephants, dolphins, corvids, and rodents. Positive emotions including play and appetitive behaviors provide evidence for states beyond simple absence of suffering. This evidence base underpins the shift in welfare science toward requiring positive welfare experiences rather than merely preventing suffering.