A crucial question at the heart of animal rights conversations: Are animals sentient? Many countries have legally declared it true, and many scientific studies concur that animals are sentient beings. But what does sentience really mean and how exactly do you measure it in animals across species? Are farm animals more or less conscious than other animals such as dogs or chimpanzees?
Sentience is referred to by Cambridge professor and biologist D.M. Broom  as the capacity of an animal to have feelings and be aware of a variety of states of being and sensations such as pleasure or suffering. Sentience or consciousness can also suggest a living being’s ability to empathize and feel compassion. Empathy and compassion are characterized by psychologists and neuroscientists as the first indications of an animal or human’s ability to be self-aware or self identify.
Assumptions and Prejudices
Let’s take a step back from psychology real quick and consider how people commonly, and often unconsciously, consider animal intelligence. Unconscious prejudices allow us to make assumptions without questioning if there’s any evidence to support it. Many people use derogatory phrases that causally joke about a lack of intelligence in animals, such as: “tiny bird brains,” “stupidly loyal” or “pig-headed.” There appears to be a common belief that human experiences like intelligence, compassion, empathy or consciousness are unique to humans.
Contrary to these widespread assumptions, Ph.D and author Mark Bekoff states  that there is “ample data” to “declare that animals are sentient beings.” Despite popular characterizations, birds are actually proven intelligent creatures and pigs have also been proven curious, intelligent and caring animals as well.
Do these common derogatory phrases fashion false assumptions? Quite possibly… very likely… some psychologists would say undoubtedly. In his book, Drunk Tank Pink, Adam Alter discusses the power of labels in shaping how we think, feel and behave. In a Psychology Today article , he explains labeling as “a tool that humans use to resolve the impossible complexity of the environments we grapple to perceive. Like so many human faculties, it’s adaptive and miraculous, but it also contributes to some of the deepest problems that face our species.”
For decades, meat and dairy companies have capitalized vastly on marketing their products as animal friendly, healthy and even “natural” or “sustainable.” Happy cows and green pastures cover their marketing merchandise. Their widely televised and commercialized images, language, and labels popularize the belief that farm animals were made for – and are even happy to be – consumed as human food. They even popularized the idea that milk creates healthier bones – a topic of heavy debate.
Scientists are now publishing studies that show a decalcifying effect of cow milk on human bones . This mass-produced, and arguably “false,” marketing by the meat and dairy industry, plus the common phrases people grow up using about animal intelligence, all influence how we view animals in contrast to ourselves.
With that in mind, I ask you to acknowledge your own assumptions – the ones that perhaps lack evidence or are based on what you assumed was true but never researched – and try to read the next piece of information with a mentally clean slate. After you do read it… think about how it feels to consider this new information with an open mind. Does it make you think differently about what food you eat, or the way you think about your pets?
Animals are Sentient
Scientists may not know to what extent animal sentience or consciousness expands, just as we’re still relatively unaware of the boundaries of our own consciousness. However, we do know that they experience: love, affection, loyalty, sadness, pain, suffering, anxiety, stress (to name a few). There is evidence to suggest that certain animals are even self-aware and have a proven “theory of mind” – the ability to recognize that others have a sense of self as well. This recognition is often measured by whether an animal can recognize it’s own ability to deceive another. A study published in the Journal of Comparative Psychology stated that pigs do indeed “exhibit complex abilities to utilize and manipulate conspecifics to their advantage in social foraging situations.” 
Cows that live alone have shown symptoms of loneliness and can develop behavioral issues without a friend to socialize with (read: The Science of Cow Friendship). Likewise, pigs have been know to develop deep affectionate bonds with humans and other animals. Cows have shown exceptional signs of pain, sadness and anxiety when their calves are taken from them or when they have been treated violently. Cows can also recognize humans and will exhibit fearful and stressed reactions when approached by humans who have previously beaten them… a clear sign of post-traumatic stress disorder.
With countless evidence that animals – in this case, farm animals – are sentient, why is there not more discourse on the ethical dilemma of using animals for human benefit? The truth about their sentience is mounting, but regardless, humans all over the world continually use animals for various purposes; we train them to do our bidding or kill them to eat or wear. Yet most people still don’t consider it exploitation, slavery or murder, which begs the question: When animals have shown cognitive ability and sensitivity comparative in measure to our own human experience, at what point do we stop considering ourselves so superior and start treating them fairly?
Ph.D Mark Bekoff states: “I’m frankly astounded that these data and many other findings about animal cognition and animal emotions have been ignored by those who decide on regulations about the use and abuse of other animals.” 
Why wouldn’t we be astounded too? Corporations would rather have their consumers blind to their own impact on the lives of sentient creatures, than risk losing profit. Is that not greed, corruption, censorship?
What Can You Do?
- Be an activist for animals.
- Be a conscious consumer: use personal choices to reflect what you truly believe is ethically correct given what you know.
- Educate yourself: do your research before you buy, before you make any assumptions.
- Refuse to be fooled by corporate marketing: question the information put in front of you. Yes, even what you’re reading now. Click the reference links below and read the research yourself.
- Share knowledge of injustices: others should be aware.
- Save and protect when possible. We are rescuing a cow soon that would have been shot and killed if not for one woman who saw it, stopped it, and saved it.
You can make a difference.
 Broom D.M. Cognitive ability and sentience: Which aquatic animals should be protected? Dis. Aquat. Org. 2007;75:99–108. doi: 10.3354/dao075099. [PubMed]
 Mark Bekoff. A Universal Declaration of Animal Sentience: No Pretending [Psychology Today]
 Adam Alter. Why It’s Dangerous to Label People [Psychology Today]
 Vivian Goldschmidt. Debunking the Milk Myth. [Save Our Bones]
 Lori Marino, Christina Colvin. Thinking Pigs: A Comparative Review of Cognition, Emotion, and Personality. [Journal of Comparative Psychology]
 Mark Bekoff. Scientists Conclude Animals Nonhuman Animals are Sentient Beings [Psychology Today]