Any vertebrate species whose intelligence has not yet been tested?

We’re reading E.B. White’s wonderful The Trumpet of the Swan with our sons. Obviously they’re very anthropomorphized swans, and they say (to each other) and do lots of things that I presume are well beyond the intellect of actual swans. I know ape, monkey, cat, dog, horse and cow IQs have been tested, and probably those of many other species too. Are there any major vertebrates whose intelligence has not yet been tested? If not, why not?

What do you mean by “major vertebrates”? Offhand, I would guess that the intelligence of less than 0.1% of all 70,000 vertebrate species has been directly tested.

On a similar note, what do you mean by “intelligence”?


Some people may have made rough comparative estimates of some types of animals’ intelligence, but testing their IQ? Putting a number on it? I don’t think so. It is not even meaningful to talk about an animal’s IQ, which is a measure of individual differences between humans (and a pretty lousy measure, even there). Animals cannot take human style IQ tests, so they can’t be compared on the same scale (or they are all at zero). Nor can different types of animals be meaningfully compared in most aspects of their behavior. The sorts of things that most clearly demonstrate the intelligence (or problem solving ability, anyway) of a chimp or a monkey usually call for use of hands, so you can’t give similar tests to a cow or a cat. Cows and cats themselves do not have the same sorts of behavioral repertoires, so their intelligence can’t be compared well in most regards either. Cats are very good at hunting and pouncing, and cows are lousy at it. Does that make cats more intelligent?

On a similar note, what do you mean by “tested?” In addition to defining intelligence, finding ways of testing for it is pretty tricky.

Recently the dog world was rocked by “scientific testing” showing some breeds to be “more intelligent” than others, because they followed directions from a human better than others. Some dog lovers and experts felt that was a poor standard for “intelligence,” artificially devaluing the capabilities of highly independent herding breeds and the like.

There are probably thousands of vertebrate species that haven’t even been discovered, let alone had their intelligence tested.

I thought I’d read somewhere - perhaps here on the Dope - that the relative intelligence of all those critters I mentioned has been tested (as difficult as it may be to rank them on a human scale). Maybe not.

Here’s a relevant article by The Perfect Master:

My favorite cartoon on the subject.

I was surprised there are only 70,000 species, but wikipedia says 64,000 described, so I guess that’s about right.

Adding up the numbers from the various classes, I came up with something like 67,000, and I’m sure there are thousands undescribed.

I’m sure he was using IQ as a short-hand form for intelligence. Aside from IQ, a controversial subject, I don’t know of any forms of intelligence tests that have consensus acceptance. But the intelligence testing in animals usually concentrates on very basic skills in comparison to humans. A thread in some other forum discusses bears being tested to recognized different numbers of symbols for a reward. Birds have been tested for their ability to solve the puzzle and use a tool to extract food from a container they can’t fit their head in. This doesn’t give clean numerical results, but it does allow certain aspects of intelligence to be compared between species.

Q. Any verterbrate not IQ tested?
A. Yes, Bigfoot.
Q. If not, why not?
A. They wouldn’t admit him to the test, because his photo ID was out of focus.