Cats vs. Dogs: Who’s Better?
This week in Parade Magazine (July 31, 2011) Kalee Thompson wrote an article about which pet was better – cats or dogs. She interviewed a number of people concerning nine different traits and concluded that while dogs outscored cats five to four, she declared it a draw because “each animal has its own special talents.” So what was the purpose of the competition? To point out the special abilities of each species? She could have done that without framing it as a competition.
Americans just love competitions, and we’re always asking “which is better?” But comparing vastly different things is silly and meaningless. It’s like asking “which is better, cars or airplanes?” It depends on the way criteria for comparison. Is it cost/mile of travel? Safety or comfort? How long it takes to get to your destination?
Even when criteria are specified, there is enormous variability in planes and in cars. Most planes are faster than most cars, but race cars are faster than crop dusting planes. Many cars are more luxurious than most planes, but some private planes are far more luxurious than off-road race cars. To come up with an overall “winner” doesn’t make much sense.
In the same way, it doesn’t make much sense to compare dogs and cats and declare one better than the other. The overall conclusions depend on the categories for comparison. Ms. Thompson chose the following: stamina, agility, fastest, longest lived, best hunter, hardest working, most independent, best sense of smell and most intelligent. We have to ask, what was the rationale for choosing those particular ones? She could have examined dozens more – best eyesight, best sense of hearing, easiest to train (but to do what should also be specified), most patient and so on. Depending upon which categories are compared, it is possible to show that cats (or dogs) are overwhelmingly better than dogs (or cats).
Even within each category, comparisons are not simple. For example, in the category “Which are better hunters?” the author dismisses the hunting abilities of trained hunting dogs, such as fox hounds, rat terriers, or Afghan hounds, and focuses on the independent hunting of cats and dogs. She relies on data from studies that show stray and feral cats kill millions of birds each year, and assumes, because there are no data for dogs, that dogs don’t kill nearly as many birds, so cats are the better hunters. If the author hadn’t focused on solitary hunting of birds, but instead looked at hunting of larger mammals, dogs might have proven more efficient. But significant individual variation exists – some cats never kill anything, while some dogs are very efficient at killing squirrels, birds, and snakes for example.
Comparing the intelligence of dogs and cats is also fraught with difficulty. Comparative psychologists have tried to find ways of comparing the intelligence of different species for over 100 years and still haven’t found a fair way to make the comparisons. Because each species is adapted to very different lifestyles it’s difficult to make direct comparisons that are meaningful. For example the fact that dogs can learn more human words than cats, says more about dog social structure than intelligence. Because dogs are adapted to live in complex social groups, we would expect social communication and remembering communication signals would be far more important than for cats, who don’t live in such structured groups.
While living a solitary life may not favor “social intelligence” there is more to intelligence than social intelligence, including learning to avoid predators and learning where food and other resources are located. As was mentioned in the article, there has been far more work done on the cognitive abilities of dogs than cats so we can’t conclude that dogs are better than cats at specific cognitive tasks. We just don’t have all the data.
Sometimes there may be good reasons to make direct comparisons between species with regard to specific abilities. For example we may want to know which species has the best visual acuity at detecting small differences in objects because we want an animal to tell us if a $20 bill is a forgery. Or which species can detect tiny quantities of volatile materials in the air, to know if accelerants are present at the scene of a fire.
So what are the take home messages? First, beware of general claims that one species is “better” than another. Such comparisons can’t be made in a meaningful way. Second, when specific comparisons are reported, ask “Why is this important?” And third, pay attention to how the specific comparisons are done. The best ones are done within a study (not drawing conclusions from studies with different methodologies) and the data gathered on both species at the same time.