By Dr. Becker
Pigs are easily one of the most misunderstood animal species. They're viewed by many as dirty and useful for little more than a food source — but in fact they're highly intelligent (and among the cleanest domestic animals).
A report published in the International Journal of Comparative Psychology reviewed cognition, emotion and personality in pigs and revealed they share many traits with animals that are considered to be intelligent.1
The findings should have major implications for the industrial livestock industry, which raises pigs on CAFOs (concentrated animal feeding operations) as though they are non-thinking objects, not intelligent beings.
Unfortunately, while it's excellent news that pigs are starting to gain some much-needed recognition, it will likely be some time before the findings permeate through to the livestock industry.
Pigs Are Psychologically Complex Animals
Researchers from Emory University reviewed dozens of studies on pigs and other animals, revealing compelling insights that pigs are psychologically complex. For instance, pigs are highly social animals and use their snouts to engage in behaviors such as rooting, carrying and pushing, and social interactions.
Pigs can also prioritize important memories, such as which site typically contains more food, anticipate positive and negative situations, and display spatial learning skills, such as learning how to navigate a maze.
Pigs are also playful animals and display many similar play behaviors as dogs. Among them, pigs may carry or shake objects such as a ball or stick, toss straw into the air, run playfully, hop around, jump, paw and scamper. They may also engage in play fighting, pushing and running after each other.
Play, it turns out, is extremely important for pigs' emotional and cognitive development. According to the study:2
"So important is this need that insufficient opportunity to explore leads to behavioral abnormalities.
Young pigs reared in a cognitively challenging and complex environment affording greater interactions with objects and other pigs are more socio-cognitively developed than their counterparts raised in standard farrowing crates found that when given access to materials allowing for exploration, pigs engaged in more behaviors associated with positive affect, such as play, and especially locomotor play.
Also, consistent with these findings is the fact that pigs make more optimistic choices (have a positive bias) when in enriched environments than in others, indicating that they find stimulation rewarding and pleasurable.
Therefore, opportunities for play and exploration impact emotional development in pigs as well."
Pig Intelligence Rivals That of Dogs and Chimps
Study co-author and neuroscientist Lori Marino, Ph.D. of Emory University and The Nonhuman Rights Project said in a press release:
"We have shown that pigs share a number of cognitive capacities with other highly intelligent species such as dogs, chimpanzees, elephants, dolphins, and even humans … There is good scientific evidence to suggest we need to rethink our overall relationship to them."
Pigs, it appears, develop sophisticated social behaviors, including competitive behaviors, as seen in some primate species. They are also sensitive to the attentional state of humans, which is also seen in dogs and primates.
For instance, young pigs can utilize human head cues to discriminate between different attention states in humans. They prefer humans who are attentive, and can also distinguish between familiar and unfamiliar humans.
In addition, pigs may show empathy; they not only connect with the emotions of other pigs but also to do so with pigs who are responding emotionally in anticipation of future events. The researchers also revealed that pigs:3
✓ Have excellent long-term memories
✓ Excel at tests requiring location of objects
✓ Comprehend a symbolic language
✓ Learn complex combinations of symbols for actions and objects
✓ Live in social communities and learn from one another
✓ Cooperate with one another
✓ Move a joystick to move an on-screen cursor (similar to chimpanzees)
✓ Can use a mirror to find hidden food
Should Intelligent Animals Like Pigs Have Rights?
Research into the sentience of pigs raises some important ethical considerations. Most people would agree that chimpanzees, dogs and other intelligent creatures, like elephants and dolphins, deserve some form of protections and rights.
Yet, pigs, which appear to be similarly intelligent, are raised in some of the most inhumane conditions on the planet.
The Nonhuman Rights Project is tackling such issues head on; they're petitioning courts to recognize that existing scientific evidence suggests certain nonhuman animals are entitled to basic legal rights, including bodily liberty and integrity.
In December 2013, the organization filed lawsuits on behalf of four chimpanzees that are imprisoned in New York. The cases, which are moving through the appellate courts, call for the chimps to be freed and transferred to live on a sanctuary.
The group intends to first focus on rights for great apes, elephants, dolphins and whales, "for whom there is clear scientific evidence of such complex cognitive abilities as self-awareness and autonomy."4 It's not a stretch that someday pigs should also be granted some form of protection or at least the ability to live out their days engaging in natural pig behaviors that are currently impossible on CAFOs. It's intriguing work, and this is only the beginning.
Marino and colleagues have also found evidence of cognitive, emotional and social complexity in chickens, and they plan to study other CAFO animals, including cows and goats, in the near future.5