What's the simplest thing humans are too dumb to grasp?
You ever see a dog that's got its leash tangled the long way round a table leg, and it just cannot grasp what the problem is or how to fix it? It can see all the components laid out in front of it, but it's never going to make the connection.
Obviously some dog breeds are smarter than others, ditto individual dogs - but you get the concept.
Is there an equivalent for humans? What ridiculously simple concept would have aliens facetentacling as they see us stumble around and utterly fail to reason about it?
"Obviously", hmm? The balance of expert opinion is in fact that dog breeds do not vary in intelligence. Which makes sense given that dog populations have significantly fewer millennia of genetic divergence than human populations, and these days nobody much claims that some human breeds are smarter than others.
You sound very certain that they are. Perhaps you should be the one who provides evidence?
As I understand it, in dogs most differences are between individuals, like in any other species. What can be said about breeds is that differences concern the application of their intelligence rather than how bluntly "smart" they are. For instance, labradors are a bit better at understanding social cues, and collies at acting on certain commands.
We did not find breed differences in tasks measuring logical reasoning or short-term memory
This makes sense. Dogs were domesticated more recently than the human lineage split between, say Aboriginal Australians and southern Africans. Would you be happy about making IQ statements for that case? If not, why exactly would it be different?
Intelligence is a pretty ill-defined measure, verging on pseudo-science in lots of case. Personally I think it is all but useless and that we would be better talking about easily measurable traits instead.
Yeah, i think working dogs and highly social breeds seem smarter, but that's just because they have been trained and/or bred for aptitude in tasks we humans deem important. If my metrics of intelligence included being an annoying little shit, I'd think chihuahuas were the smartest breed.