Given that humans can be pretty well described as a very in-our-own-heads kind of species, we can't help but repeatedly pontificate about the thought processes of other animals. Many studies have attempted to quantify the complexity of thought with respect to a broad variety of animals; some even focus on specifically determining whether cats are smarter than dogs or not despite the severe subjectivity of the term, smarter. Putting together the results of lots of research on the subject, though, suggests to some that it's really just impossible to tell.

To honor the Chinese Year of the Dog and Lunarfest, Yale PhD candidate Angie Johnston used her research to help us peer into the minds of dog. Doing most of her research at the Canine Cognition Center, Johnston gave a talk on the subject at an event, analyzing how dogs communicate and what dogs are actually thinking from moment to moment. "People love their dogs and want to know what they're thinking, but we can't ask them," she explained. "The only way we can find out what they're thinking is by getting these different studies to try to get inside their head."

Researchers at the Canine Cognition Center managed to learn more about canine problem solving by introducing hounds to basic games. Johnston said this provided insight into the canine worldview. These were problem-solving games that the researchers played with the dogs that participated in their study, and canine volunteers were awarded diplomas for their participation. Johnston pointed out that the whole reason dogs are considered man's best friend today is because of their problem-solving proficiencies; they first began a process she calls self-domestication some 14,000 years ago by infiltrating human camps for food as an alternative to hunting and foraging.

That's considered an evolutionary milestone for dogs, and another came about 2,000 years ago, according to Johnston. This is when humans truly came to understand the use value dogs represented and began to breed them. It's well documented that human beings experience oxytocin reactions in the brain when conveying or feeling love for other humans, and the same has been found to be the case between humans and dogs in copious, documented studies, which marks another evolutionary milestone. "When you see the same hormone released in dogs and families that are released in humans and infants, it suggests that some really similar things are going on," said Johnston. "So, I think dogs do love us."

She adds that this discovery has actually distinguished domesticated dogs from wolves who remain seemingly too feral to experience this oxytocin connection even if they live with people. "It's something dogs have developed and as they have lived with us, it has grown into true love," Johnston elucidated. This actually makes dogs uniquely similar in brain construction to humans for a species completely unrelated to our species, which is why new studies are suggesting that dogs actually have a slight edge against cats in the debates about which is more intelligent.

The neural construction of the canine brain is ostensibly the superior construct, yet some studies still find that cats are either better problem solvers in certain circumstances or in some other way more sophisticated. The bigger problem with all these lines of research, though, is that, when administering intelligence assessment tests to cats that require logical deductions or counting or whatever else, a study published in Frontiers of Neuroanatomy has found that cats simply have a greater proclivity to be as unhelpful as possible, which may skew research results.

The research team for this study contrasted neural connection levels in the brains of eight different species: brown bears, lions, hyenas, dogs, cats, raccoons, banded mongooses, and ferrets. All these mammals are known for their intelligence relative to other mammals aside from primates. For instance, a 2018 study filmed for Big Cats, a BBC program, showed that lions are able to watch people set up and manage a food trap only once and are then able to manage those traps themselves. Cats, however, were found in the Frontiers of Neuroanatomy study to have fewer neurons than dogs, and this included lions. It also pertained to bears as well, and much of the scientific community accepts this as definitive proof of superior intelligence in canines.

There's a caveat, though. Animal intelligence isn't directly correlative to the neuron count in the first place, and though they do account largely for complex cognition, the relationship between neuron quantity and intelligence isn't fully understood. One reason for this discrepancy is that cognition is shaped by how the neurons are distributed within the brain. For example, elephants have far more neurons than we do, and their brains are a lot bigger than ours according to a study conducted in 2016; however, 98 percent of the neurons in an elephant's brain is concentrated on the cerebellum, which is at the base of the brain near the brain stem. For humans, the majority of our neurons reside in the prefrontal cortex, which is the site for the most complex thoughts.

Beyond this, cats in particular demonstrate time and again a lack of willingness to cooperate with humans in laboratory settings the same way they do in a cat owner's home or anywhere else. This is because cats are endowed with far greater senses of free will. An expert on this, David Grimm, said back in 2014, "We did one study on cats — and that was enough!" alluding to their unruly behavior. Another expert specifically on animal affinities for numerical ability, Christian Agrillo, told Grimm that, when cats are tested on cognitive abilities like counting, "they just walk away." In other words, feline free will can very easily obscure the results of a myriad of studies on cat intelligence, especially given how many empirical or anecdotal, out-of-lab examples there are of complex thought in cats.

[researchpaper 리서치페이퍼=Cedric Dent 기자]