Why don't you see retarded animals?

Factual Questions
1

According to the March of Dimes website, 1 out of every 28 babies born suffers from a “serious” physical or mental handicap. According to one study by the CDC it’s 3.3%.

So why don’t you see at least a comparable percentage of animals, from deer to kangaroos to housecats to guinea pigs to iguanas to mutts, walking around with Marfan’s Syndrome, Down Syndrome, club feet, Cri–Du-Chat Syndrome, and so on? Why don’t we see deer with Prader-Willi syndrome, grossly obese and mentally deficient, but otherwise capable of snuffling around for grass to live on?

I’m not referring to physical defects so severe that they die at or shortly after birth, since the type of high-tech maintenance is not as readily available to animals as to humans in a birth setting.

I know we’re probably all seen or heard of someone’s litter of pups that had a dead one, or one with the odd cleft palate/lip/nose (which tends to dramatically shorten its life due to feeding/breathing difficulties). I’m referring to animals with non-lifethreatening anomalies, such as mental retardation of one sort or another.

But there’s lots of people around, that happily live out their lives, who happen to have one physical or mental anomaly or another, that didn’t require heroics to allow them to live. It’s not that uncommon to see someone at the mall, or at the local Wal-Mart, who’s obviously got Down Syndrome or some other problem. How come you never see a dog, or a cat for that matter, with the telltale facies of Down Syndrome?

There is, like with humans, a spectrum of intelligence. But it seems that it’s a much narrower range. I realize that our measurements are hard to apply to the non-human population. However, if someone/somedog/somecat/somewallaby is so superlative, shouldn’t it be noticeable and if so, measurable? And at the other end of the spectrum, yes, we all have had dogs we just said were “dumb as dirt.” But how do we classify a dog as clinically retarded, versus just thick headed?

And who could tell? What’s the criteria for subnormal intellect in, say, a chipmunk?

Are animals much more likely to self-abort a fetus that is anomalous in some way, and that’s why we don’t see many of them? Doesn’t that defeat the purpose of evolution? I know that some animals will kill a defective newborn; i.e. cats, dogs, and even horses (surprised me). How can they tell if the baby is “not quite right,” and if they can, what does that say about human instincts towards an “other than normal” person?

Wild animals, of course, are not going to live long in the wild, if born with defects incompatible with life or the provisioning thereof. Natural selection tends to weed them out.

Googling on this subject a long time ago, I found a picture of a kitten who was said to have Trisomy 21, but can’t find that cite any more. And he looked weird. Was that for real? Acoording to the NDSS website, 1/300 live births have one of the Trisomies…21, 18, 13, or one of the sex chromosome anomalies. But of the last ten thousand or so cats I have seen, none of them looked…well…like they had something wrong with them. Not saying anything about the weird looking dogs that just look weird, like pugs, Shi-Tzus, or Bug-Eyed Yappers, who have had many generations of genetic mutation/defect bred into them for definition.

It just seems that congenital defects, including retardation, are postively common in humans, so why not in animals too?

2

In the case of wild animals, being dumber than the average bear is the kiss of death. You either need to catch food, or avoid being caught as food, and I don’t think that many animals expend a lot of energy on being smarter than they absolutely must, so being sub-par is fatal.

As to birth defects in general, last summer I sat in the train station of Trento, Italy for an hour and a half watching a pigeon with a clubfoot get along in life, quite well.

3

Also–and I’m sure you realize this–other animals do not have the same chromosomes that humans do, therefore will not have the same chromosomal disorders such as Downs, Prader-Willi, etc.

4

One guess (and I apologize for venturing a guess in GQ) is that the general lack of higher-order thinking skills amongst non-human animals means that there is less differentiation between the normal and the deficient. That is, maybe ther are there, but it’s harder to tell.

I mean, I’ve heard people (actually, the esteemed HelloAgain) say that horses are a lot like four year olds. A four year old human with mild retardation is not that different from a normal four year old human. The situation is different when you start talking comparing impaired vs. normal people at the level of teenagers or adults–who have thinking skills that even “smart” animals aren’t capable of.

I’m guessing the truly slow-witted will meet a Darwinian fate, but the rest may live out their lives without humans realizing they’re different.

5

I have to let you meet my dog some day.

6

But there are lots of causes of mental retardation besides chromosomal disorders. Like you said, though, most animals with such problems will die very quickly.

7

We need a naturalist. However, I do believe that most animals simply refuse to care for a newborn that is too “different” than the norm.

8

I don’t think that the OP realizes quite how intense selection against congenital defects is in wild animals. Mortality in most species is very severe in the early stages of life. It is unlikely that, under natural conditions, any animal that has a anomaly that gives it a significant disadvantage in finding food or avoiding predators is going to survive to adulthood. That would include the degree of mental incapacity seen in “retarded” humans relative to average individuals.

Sometimes domestic animals or animals that receive food or care from humans will survive even if they have defects, but they would be very unlikely to in the wild.

In the particular case of trisomy 21 (Down’s Syndrome), however, I would point out that in humans this is associated with older mothers, and virtually no other animals have a reproductive life anywhere near as long as a human’s. Most animals are simply not going to live long enough, let alone reproduce long enough, for this kind of chromosomal defect to be produced.

9

There are definitely some animals that have lived to adulthood that aren’t too bright. For example, take the robin that would fly directly into my kitchen window about a hundred times a day for several days in a row. He’d conk his head on the window, drop to the ground and look dazed (as much as a bird can look dazed), fly up and proceed to do it again…and again… and again. Where’s Darwin when you need him?

10

I would doubt that human Down’s Syndrome babies or those with related mental defects survived very long after weaning, iprior to the development of civilization.

11

I had a cat who was too dumb to clean himself. He was always covered with dirt and burrs, and his fur had clumps of I don’t know what in it. He looked exactly like “Bill The Cat” from Bloom County.

12

Well, the first time was probably an accident. Windows with reflections are pretty deceptive, since the image in them gives the preception of depth.

So, the first time was an honest mistake. Then his short-term memory was damaged by the impacts, so he just never learned that the image in your window was not real. So then he did it a few hundred more times until he finally killed himself.

13

More likely, the Robin saw his own reflection as a territorial rival and was trying to drive it out of its home turf. It wasn’t being “stupid” at all in Robin terms, it just lacked the capacity to understand that a reflection wasn’t a real bird. And birds and other animals can become extraordinarily single-minded when a threat to their reproductive success (for which holding a territory is usually necessary) is involved.

14

2 of my cats are incredibly intelligent, the other one is so incredibly dumb, if she’s not retarded, she’s got to be pretty damn close, IMO. (And she’s the offspring of the smartest of all of 'em…her mother has taught herself how to open doors, amongst other things).

She’s very sweet and loving, but…holy crap, she’s dumber than a box of rocks. She really never mentally matured past about 6 months, she’s almost 3 and still acts just like a very young, incredibly dumb kitten.

If she ever got loose and had to survive on her own, I wouldn’t give her more than a week, personally.

15

My grandmother had a dog which I believe was at least slightly retarded, and I say that with all seriousness.

Once my dog and hers were in the same room. I tossed both dogs a treat. Her dog’s treat accidently rolled beneath the coffee table. The dog whimpered, tried to squeeze his head in, and when that didn’t work, sat and barked at the treat. After eating her own, my dog looked at him, looked at the treat, and promptly walked over to the table, stuck her leg under it, scraped the treat towards her, and when it got close enough, picked it up and ate it.

He could not solve simple problems that were easily within the grasp of my dog. For example, if a treat was laying on the floor on the other side of an open glass door, he would ram into the glass, rather than walk around the door frame to the other side to get to it.

If he wrapped a leash around a tree, he couldn’t figure out how to untangle himself. My dog in the same situation backed up around the tree the way she came, freeing herself. He would wrap around again and again until he nearly choked himself.

These are just a few examples. To say the least, the dog was very slow. It took him a very long time to learn the simplest tricks-- which he promptly forgot. From my experience with him, I would certainly say that animals can be retarded.

In the wild, a “slow” animal would quickly be eaten. In domestic animals, there’s no natural selection. The “dumb” ones get fed and cared for the same as the smart ones. Secondly, I stongly suspect his genes had a lot to do with it: he was a “pure blood”-- and his family gene pool seemed remarkably small.

16

Shouldn’t a mammal recognize when a method doesn’t work? After the first dozen concussions, I would’ve thought that the robin would have tried a different tactic. I guess they don’t call ‘em bird brains for nuthin’.

17

Wellll, a robin isn’t a mammal, first off.

Secondly, the robin’s entire point of living is to breed. If he sees a percieved threat to that point, he’s gonna do what he can even if that means bashing into your window 20 times. He doesn’t know he’s not hitting a really hard bird.

It’s not really the sort of thing that makes sense to consider from a human or mammalian, perspective

18

Dimwitted animals become prey to predators and automobiles. It is the predator’s duty to cull out the slow and the dimwitted. Sadly, it is also the motorist’s duty. (The cello solo goes here.)

19

I hear that you can’t train a retarded lab mouse to walk through a maze. I suppose one could use the maze itself as a test of retardation in lab mice.

20

Well in my head, I typed animal, not mammal. That’ll teach me to post when I’m tired. :smack: