Comparing intelligence in animals is such a hard thing to do when we barely understand it in ourselves. As they say in the article, we frequently consider dolphins more intelligent because they are more sociable and exhibit similar characteristics to us.
An easy (although not necessarily correct) way to define intelligence could just be the ability to learn, although even this can be hard to define. Some animals can learn fast, while others have a larger space in their memory. As was pointed out, dogs are able to learn significantly more words and more complex phrasing than other animals, but at the same time they have been conditioned for a very very long time to understand human voices, dolphins much less so.
Dolphins are in a completely different environment, which results in completely different conditioning. Perhaps the reason they seem similar to us is because they are in a similar place in their environment. They're fairly independent species, not relying too heavily on other species, or being heavily preyed on by other animals. This could allow their brains to evolve in a similar way to ours, which aligns with our definition of intelligence.
Another problem in "dog intelligence" is that a lot of it is misconstrued with obedience. Sure, dog A and dog B both understood the command you issued; and the one that gets labelled as "intelligent" is the dog that chose to follow that direction versus the other dog who made up his own mind as to what to do.
Most scent hounds are perfect examples of this. They never have high representations at obedience competitions, but put an obstacle between them and what they are tracking, and you will see amazing problem solving skills.
You are absolutely right. I heard on one of the 9/11 shows there was a very limited number of dogs capable of working at that type of scene searching for people/bodies. And by limited I think it was like < 30 in the entire world.
At home I have a rottweiler(ruby) and she is really smart and obedient. She is driven by life. If that makes sense. My brother a has a doberman and the dogs hang out all day every day, but the doberman is driven by food. When we used to have the doberman at the junk yard she would run around through broken glass and other stuff and always be fine. I can teach both dogs any trick in the world, but the doberman has this innate unexplainable overriding intelligence through problem solving. It's pretty cool.
Somewhere around object persistence and planning actions: I once saw a rodeo clown's dog in a comedy bit where the clown would remove something from a barrel and the dog would put it back in when he turned around.
Once, the dog missed dropping the object in the barrel--and then picked it up and did it again, this time getting it in the barrel. That dog knew he was performing a certain task, and not just an action. That's stuck with me as a pretty impressive feat of canine cognition.
Dogs have specifically been breeding to perform these tasks, while dolphins just can do it "out of the box". Also i suspect killer whales would out do dolphins in many tasks, especially those requiring social intelligence and language. Maybe elephants wouldn't do much worse either, but they were probably too difficult to study because of their size.
Dogs have been bred to perform these tasks, but they've also evolved to become dependent on humans. If humans had never entered the situation, who knows where the intelligence of other animals would be.
Crows as well. One radio report I recall discussed how they not only recognize human faces but can inform others about individuals that threaten them. The researcher who was featured has to wear a mask when he is performing experiments or else he risks being attacked by other birds while walking around campus...
I don't know if there is any truth to this, but I have heard that octopus have a "different" sort of intelligence than we are used to. It's more innate to them, so they are capable of learning much less but they have some very advanced "pre-baked" capabilities.
Most of what I've seen is that they have fairly amazing learning ability when it comes to problem solving, and also when it comes to applying observations of other octopi solving problems (e.g., an octopus can figure out how to work mechanical things that pose barriers to food, and one octopus can watch another octopus work such an mechanism once to learn how to do it themselves.)
It seems to me that a lot of wild animals are smarter than dogs. Dogs' main ability is to "connect" to us and rad our intentions. On the other hand they are dependent on us and probably not very good at surviving in the wild.
For the downvoters (3 of you): it's perfectly reasonable to ask for a TLDR, so STOP FUCKING DOWNVOTING.
The article was quite long. I may be interested in reading it, but I didn't have time (actual work and life stuff to do, you know). However if I can read an abstract of the study (or at least a TLDR) I can get the info and decide whether I want to read the full article.
An easy (although not necessarily correct) way to define intelligence could just be the ability to learn, although even this can be hard to define. Some animals can learn fast, while others have a larger space in their memory. As was pointed out, dogs are able to learn significantly more words and more complex phrasing than other animals, but at the same time they have been conditioned for a very very long time to understand human voices, dolphins much less so.
Dolphins are in a completely different environment, which results in completely different conditioning. Perhaps the reason they seem similar to us is because they are in a similar place in their environment. They're fairly independent species, not relying too heavily on other species, or being heavily preyed on by other animals. This could allow their brains to evolve in a similar way to ours, which aligns with our definition of intelligence.