Key signatories
Stephen Hawking witnessed the signing. Philip Low, Jaak Panksepp, and dozens of leading neuroscientists concluded mammals, birds, and even octopuses have the neurological substrates for conscious states.
Smarter Than We Thought
- Pigs perform as well as chimpanzees on some cognitive tasks (Cambridge, 2015).
- Chickens demonstrate self-control, empathy, and object permanence (Bristol, 2017).
- Cows form lasting social bonds and show distress when separated from companions.
SPECIES BY SPECIES
Pigs
IQ comparable to 3-year-old human children; play video games with joysticks (Purdue, 2021); demonstrate empathy by responding to distress of peers; pigs have episodic memory (remember specific events); dream during REM sleep.
Chickens
Self-control demonstrated in marshmallow-test equivalent; mother hens show empathic response when chicks are distressed (Bristol University); object permanence (understand objects exist when hidden); basic arithmetic (can count to small numbers); complex social hierarchies with memory of 100+ individuals.
Cows
Long-term memory (remember locations, faces, events for years); show positive affect when solving puzzles (Cambridge ear-posture studies); form friendships — heart rate and cortisol both increase when separated from bonded companions; evidence of grief behavior.
Fish and octopuses
Cleaner wrasse pass mirror self-recognition test variant (2019, PLOS Biology); octopuses show play behavior and individual personalities; fish exhibit social learning and pass cultural information to offspring.
THE KEY FINDINGS
Pigs
Outperform 3-year-olds on some cognitive tests
100+
Individual flock members chickens can recognize
2019
Year fish passed a version of the mirror self-recognition test
2012
Cambridge Declaration on Consciousness signed by neuroscientists
The Cambridge Declaration on Consciousness (2012)
In 2012, a prominent international group of neuroscientists signed a declaration at Cambridge University concluding that non-human animals possess the neurological substrates for conscious experience.
What they found
Subcortical neural networks supporting emotional experience are not unique to humans. The limbic system, shared across mammals, generates affective states. Birds have analogous structures.
The implication
If consciousness is substrate-independent and not unique to the human cortex, then the overwhelming evidence of emotional and cognitive complexity in farm animals demands moral consideration.
Cognition Changes the Moral Calculus
Understanding that farm animals have complex inner lives should change how we treat them.
🔬 Follow the research
Read new work in the Animal Cognition journal.
🐷 Visit an animal sanctuary
Support places like Farm Sanctuary or Woodstock Sanctuary.
🌱 Let cognition inform your diet choices
Small changes add up when grounded in respect for animal intelligence.
📚 Read
Are We Smart Enough to Know How Smart Animals Are? — Frans de Waal (2016)
Learn More About Animal Minds
Explore how cognition research connects to daily welfare choices and public myths.