Rapid advances in neuroscience, behavioral research, and cognitive science are continuously expanding our understanding of which animals can suffer and experience positive states.
Sentience research is expanding both the breadth of animals recognized as potentially sentient and the depth of understanding of sentient experience. Technologies including functional MRI, connectomics mapping of neural circuits, and more sophisticated behavioral paradigms are revealing cognitive and affective capacities in species previously considered non-sentient. The trajectory of this research consistently moves toward recognizing greater sentience across more taxa. Applied to welfare, this research trajectory suggests that the circle of moral concern will continue expanding. Planning now for welfare frameworks that can accommodate this expansion — rather than retrofitting welfare protections after sentience is established — would reduce future suffering at scale.