# Is there a normal distribution of intelligence among bears? **URL:** \ **Category:** Factual Questions\ **Created:** [November 8, 2018, 2:13am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172 "2018-11-08T02:13:35Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![SayTwo](https://avatars.discourse-cdn.com/v4/letter/s/e56c9b/32.png) [@SayTwo](https://boards.straightdope.com/u/SayTwo)\ **Post date:** [November 8, 2018, 2:13am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/1 "2018-11-08T02:13:35Z")
If so, how is it made manifest? ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 8, 2018, 2:38am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/2 "2018-11-08T02:38:03Z")
There’s a distribution of intelligence in pretty much every mammal species. Why are you asking, specifically? Except maybe koalas. They’re exceptionally stupid as a rule. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [November 8, 2018, 2:38am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/3 "2018-11-08T02:38:46Z")
> [@SayTwo](#): > > If so, how is it made manifest? Well, there have been incredibly smart bears like [Yellow-Yellow](https://rootsrated.com/stories/the-legend-of-yellow-yellow-new-york-s-most-infamous-bear) who managed to figure out how to open food canisters designed to stop bears, and taught the methods to her offspring. No other bears figured it out, so she was an outlier. Intelligence is hard enough to measure in humans, so any measurements for bears are going to based on a few simple tasks, like problem solving. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 8, 2018, 2:53am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/4 "2018-11-08T02:53:31Z")
> [@SayTwo](#): > > If so, how is it made manifest? The manifestation is that some bears are dumber than the average bear, and some bears are smarter than the average bear. ---
**Author:** ![Jonathan\_Chance](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jonathan_chance/32/701_2.png) [@Jonathan\_Chance](https://boards.straightdope.com/u/Jonathan_Chance)\ **Post date:** [November 8, 2018, 2:57am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/5 "2018-11-08T02:57:08Z")
Hey, BooBoo! ---
**Author:** ![Beckdawrek](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/beckdawrek/32/3647_2.png) [@Beckdawrek](https://boards.straightdope.com/u/Beckdawrek)\ **Post date:** [November 8, 2018, 3:53am UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/6 "2018-11-08T03:53:17Z")
Those food canisters are a good bit better than Yogi’s pic-a-nic basket. Wow, smart bear. I agree with the fact that any mammal can be just dumb. I have a developmentally delayed Yorkie sitting on my lap staring at her foot, trying to figure out what it is. I assume a lack of oxygen at birth or an injury could account for some animals having differing levels of intelligence. Take the pig. They are considered pretty smart creatures. We have a colony of feral hogs roaming close to us and I’ve seen them do some dumb crap. We had an electric fence around my vegetable garden to keep the hogs out, the dummies would bite at it, getting shocked repeatedly. I couldn’t stand it. I bought corn and sprinkled it around my patch and commented how dumb they were. Mr.Wrekker said they were pretty smart to get me to go buy and serve their favorite food. Hmmm!?!? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 8, 2018, 2:09pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/7 "2018-11-08T14:09:33Z")
I once saw an intelligence test for dogs, consisting of a set of tasks that some dogs could figure out, but others couldn’t. I imagine that a similar test could be adapted for bears. But of course, humans interact with bears much less than we do with dogs, so the bear version probably hasn’t been developed or deployed. As far as intelligence having a specifically _normal_ distribution, though, that depends on having some way to quantify it. One can come up with some sort of test, and say that those animals with a higher score are more intelligent than those with a lower score, but can you say (for instance) that an animal with twice the score of another is “twice as intelligent”? Can you even say that one gap between scores is “twice as large” as another gap? Without being able to say things like that, you can’t determine what sort of distribution you have. With human tests, in fact, the usual procedure is to feed the raw scores through a function designed to turn it into something that has a normal distribution, and then assert that that exactly-normally-distrubuted artificial statistic is “real intelligence”. **Beckdawrek** , you don’t need to invoke calamities like abnormal births (which aren’t as common among non-humans, anyway) to explain differences in intelligence. Animal intelligence would vary for all the same variety of reasons as human intelligence. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 8, 2018, 3:16pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/8 "2018-11-08T15:16:05Z")
> [@Chronos](#): > > …As far as intelligence having a specifically _normal_ distribution, though, that depends on having some way to quantify it. One can come up with some sort of test, and say that those animals with a higher score are more intelligent than those with a lower score, but can you say (for instance) that an animal with twice the score of another is “twice as intelligent”? Can you even say that one gap between scores is “twice as large” as another gap? Without being able to say things like that, you can’t determine what sort of distribution you have. With human tests, in fact, the usual procedure is to feed the raw scores through a function designed to turn it into something that has a normal distribution, and then assert that that exactly-normally-distrubuted artificial statistic is “real intelligence”. But you make this sound rather more unscientific and _ad hoc_ than it really is. There are many different possible tests you can do to measure cognitive ability. The notion of a general intelligence factor _g_ arose from evidence that the results of a wide variety of such tests are positively correlated, with _g_ explaining about half the variance. And the assumption of a normal distribution is a reasonable one. Barring major mental defect (i.e. away from the tails of the distribution) the distribution of innate general intelligence is almost certainly attributable to the combined influence of variation at many genetic loci (a single gene with large effect would have been found), so the Central Limit Theorem implies a normal distribution. There’s a Wiki article on _g_ in non-humans, apparently it’s quite similar in primates and rodents, explaining about half the innate variance in cognitive tests. > **[g factor in non-humans](https://en.wikipedia.org/wiki/G_factor_in_non-humans)** > > The g factor, or general factor, of intelligence is a psychometric construct that summarizes observed correlations between an individual’s scores on various measures of cognitive abilities. First described in humans, a g factor has since been identified in a number of non-human species. > Non-human models of g have been used in genetic and neurological research on intelligence to help understand the mechanisms behind variation in g. > Most measures of g in humans, including most IQ tests, rely heav... ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [November 8, 2018, 3:21pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/9 "2018-11-08T15:21:13Z")
A black bear cub/yearling was recently seen in my area running around with its head stuck inside a big plastic pretzel jar. Just saying. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [November 8, 2018, 4:11pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/10 "2018-11-08T16:11:59Z")
> [@Telemark](#): > > Well, there have been incredibly smart bears like [Yellow-Yellow](https://rootsrated.com/stories/the-legend-of-yellow-yellow-new-york-s-most-infamous-bear) who managed to figure out how to open food canisters designed to stop bears, and taught the methods to her offspring. Except her oldest cub, Mellow Yellow, who didn’t seem very interested in learning anything at all. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [November 8, 2018, 4:29pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/11 "2018-11-08T16:29:26Z")
Well, yes, there’s definitely some real trait there which can at least be ranked. And yes, a normal distribution probably is a reasonable assumption, absent any specific reason to use some other distribution. It’s just not really a testable assumption. There are also ways to do meaningful statistics on data without assumptions of distributions, using nothing more than rank data. And it behooves researchers to learn about those methods, because often (more often than statistician like to admit), the assumptions that lead to normality fail in one way or another (especially in the tails of the distribution). ---
**Author:** ![CookingWithGas](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cookingwithgas/32/485_2.png) [@CookingWithGas](https://boards.straightdope.com/u/CookingWithGas)\ **Post date:** [November 8, 2018, 6:02pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/12 "2018-11-08T18:02:59Z")
Without knowing anything about how to measure intelligence or anything about bears I would be putting my money on a normal distribution. Is there any natural measurable trait of any species that is not normally distributed? It seems the trick here is defining what is intelligence in a bear, and then determining how to measure it. ---
**Author:** ![thelurkinghorror](https://avatars.discourse-cdn.com/v4/letter/t/7c8e57/32.png) [@thelurkinghorror](https://boards.straightdope.com/u/thelurkinghorror)\ **Post date:** [November 8, 2018, 6:11pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/13 "2018-11-08T18:11:56Z")
> [@John\_Mace](#): > > Except her oldest cub, Mellow Yellow, who didn’t seem very interested in learning anything at all. Quite rightly. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 8, 2018, 6:41pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/14 "2018-11-08T18:41:10Z")
> [@CookingWithGas](#): > > It seems the trick here is defining what is intelligence in a bear, and then determining how to measure it. Well, as with humans (and the primate and rodent studies I noted above) the approach would be to devise numerous different cognitive tests, and then determine to what extent the correlation between the tests is explained by a general intelligence factor. ---
**Author:** ![carnivorousplant](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/carnivorousplant/32/3563_2.png) [@carnivorousplant](https://boards.straightdope.com/u/carnivorousplant)\ **Post date:** [November 8, 2018, 8:16pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/15 "2018-11-08T20:16:16Z")
> [@thelurkinghorror](#): > > Quite rightly. There ought to be a law. ---
**Author:** ![TSBG](https://avatars.discourse-cdn.com/v4/letter/t/77aa72/32.png) [@TSBG](https://boards.straightdope.com/u/TSBG)\ **Post date:** [November 8, 2018, 8:19pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/16 "2018-11-08T20:19:53Z")
I’ve seen YouTube videos. Bears can climb into hammocks and destroy suburban swimming pools. I think they might be coming to the end of a long period of just observing us and entering the “takeover” phase. ---
**Author:** ![Shodan](https://avatars.discourse-cdn.com/v4/letter/s/9f8e36/32.png) [@Shodan](https://boards.straightdope.com/u/Shodan)\ **Post date:** [November 8, 2018, 8:40pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/17 "2018-11-08T20:40:37Z")
> [@CookingWithGas](#): > > It seems the trick here is defining what is intelligence in a bear, and then determining how to measure it. Also > [@](#): > > Bruce Schneier discusses the security issues related to bears in national parks, and quotes a park ranger: > > There is considerable overlap between the intelligence of the smartest bears and the dumbest tourists. [Cite](https://northernplanets.blogspot.com/2006/08/smarter-than-average-bear.html). Regards, Shodan ---
**Author:** ![sitchensis](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/sitchensis/32/4892_2.png) [@sitchensis](https://boards.straightdope.com/u/sitchensis)\ **Post date:** [November 8, 2018, 8:43pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/18 "2018-11-08T20:43:22Z")
My assumption is that it would be a light-tailed distribution with very little variance and few outliers. They are not social creatures and there is some harsh selection against dumb ones. ---
**Author:** ![Riemann](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/riemann/32/3133_2.png) [@Riemann](https://boards.straightdope.com/u/Riemann)\ **Post date:** [November 8, 2018, 9:28pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/19 "2018-11-08T21:28:12Z")
> [@sitchensis](#): > > My assumption is that it would be a light-tailed distribution with very little variance and few outliers. They are not social creatures and there is some harsh selection against dumb ones. Why would selection against being dumb narrow the variance rather than increasing the mean? ---
**Author:** ![Quercus](https://avatars.discourse-cdn.com/v4/letter/q/7ab992/32.png) [@Quercus](https://boards.straightdope.com/u/Quercus)\ **Post date:** [November 8, 2018, 9:57pm UTC](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172/20 "2018-11-08T21:57:01Z")
> [@CookingWithGas](#): > > Without knowing anything about how to measure intelligence or anything about bears I would be putting my money on a normal distribution. Is there any natural measurable trait of any species that is not normally distributed? Sure, plenty. Number of limbs, for instance. [Next page](https://boards.straightdope.com/t/is-there-a-normal-distribution-of-intelligence-among-bears/824172.md?page=2)