Animal sentience and consciousness
Sus scrofa domesticus
Pigs are highly intelligent and sentient animals with cognitive abilities comparable to dogs and 3-year-old children. They demonstrate self-awareness, complex social structures, emotional depth, and sophisticated problem-solving abilities.
Plants respond to damage and stress, but they lack neurons and brains, and mainstream scientific reviews argue plant consciousness/sentience is extremely unlikely. The plant “pain” idea typically confuses signaling/defense responses with subjective experience.
Evidence for insect sentience is growing but remains less certain than for vertebrates; a precautionary approach is reasonable. Veganism typically reduces direct harm to large, clearly sentient animals and reduces land use—likely reducing many forms of animal suffering overall, including incidental insect deaths.
Many jurisdictions and scientific reviews increasingly recognize strong evidence for sentience in cephalopods and decapod crustaceans (e.g., learning, flexible behavior, responses consistent with pain). This has driven policy recognition in some places.
Many researchers argue fish have the neural substrates and behavior consistent with pain experience, while some dispute the interpretation of behavioral evidence. The evidence base supports *precautionary* welfare treatment of fish as sentient, but scientific debate persists on subjective experience details.
The scientific mainstream accepts that mammals and birds have the neurological and behavioral capacity for pain and other affective experiences. This is reflected in broad scientific consensus statements and welfare science.
Sentience is about the capacity for subjective experience (e.g., pain/pleasure), not IQ. Moral concern in most frameworks is tied more to the capacity to suffer than to intelligence.
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