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'Wassup, Sheep?' He Asked

Friday, May 02, 2014 - 08:00 AM

One man is facing a few hundred sheep. He has questions. When he shouts to them, the sheep — surprisingly — answer back. It's a very lively back and forth, with one obvious problem. I don't trust these sheep. Their answer to his "Are you happy?" question seemed oddly, even suspiciously, short. Are they hiding something? Or are they — and I mean this with the greatest respect — a little dim?

 

YouTube

I'm going with "dim" here. These sheep are domesticated animals. They live to be shorn or eaten by humans. In 2005, zoologist Dieter Kruska described changes in various mammalian brains over time, and found that domesticated sheep brains are smaller than wild sheep brains.

This is not just a sheep thing; it's a trend in domesticated animals. Domesticated pigs have smaller brains than wild boars. Lab rats have smaller brains than wild rats. Dog brains are smaller than wolf brains. Same for domesticated ducks, domesticated geese, domesticated horses — when you get bred for gentleness, for human uses, apparently you get stupider.

Well, "stupider" may not be fair. Brain size doesn't always correlate with intelligence. On some tests, laboratory rats outperformed wild rats, and domestic guinea pigs did better than wild cavies. But most of the time, writes evolutionary biologist and science blogger Christie Wilcox, when the test is about puzzle solving, wild animals win:

Dogs, for example, appear to be a few crayons short of the box when compared to wolves. A study in 1985 found that wolves vastly outperformed malamutes in getting a food dish from a series of complex puzzle boxes. And while one study had found that dogs are better able to pick up human social cues than wolves, they were criticized for using wild wolves that had little interaction with people. Indeed, when another set of researchers did the same kind of study using wolves that had been raised by humans, the wolves beat the dogs hands down.

The Price Of Nice

These changes don't happen instantly. When a wild pigeon gets captured, its brain doesn't shrink. The transition is gradual, across generations, in the animal's DNA. Presumably, domestic beasts are selected for certain qualities — tameness, friendliness, cooperativeness. Which may (or may not — scientists are still arguing about this), lead to a slightly duller animal, like the ones bleating in our video.

Interestingly, this development seems to include us.

NPR reported a couple of years ago that human brains have gotten smaller over the past 10,000 years. About 10 percent smaller. Our skeletons are also a little lighter, our foreheads a little flatter. Duke University's Brian Hare told my colleague Jacki Lyden that these changes — and smaller brains — are a "signature of selection against aggression," meaning we may, on the whole, be less brutish than we used to be. The most violent among us are more likely to be culled (bye-bye, Saddam, Osama, Idi, Adolph; hello, Alan Alda). We have begun, Hare thinks, to domesticate ourselves. That's nice to hear, but going back to the sheep video: What if the price of getting nicer is that we turn a wee bit duller?

I like the niceness. But I want the brightness. Will nature make us choose?

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Comments [8]

Vanessa from Maryland

A small brain does not actually mean that the animal is more stupid than the animal with the bigger brain. I rembember reading once that it was more about the percentage of the brain you use. Just because the physical mass is smaller does not mean that the percentage used is less. In fact it's been said that a smaller brain using he same percentage of a bigger brain is MORE intelligent. This also does not mean that the sheep are smarter for having the smaller brain than the wild sheep. Unless there was a way to see which one was using a higher percentage of their brain.

May. 06 2014 06:11 PM
Alden

Sounds like general democratic and republican voters repeating the same bs their candidates lie over and over and over and over.

May. 06 2014 02:18 PM
sepiae

I concur with nor and Daniel from Minnesota - although there should be a difference in degrees: the way sheep are help in captivity, provided it's broad range grass land, doesn't compare to the coffin-tight incarceration of orcas.
It's not surprising on the whole: not only has captivity, must have even if one is born into it, be it as a sheep or chicken, a dulling effect. More important, I'd think, is the lack of challenge. Of situations providing life-important reactions/decisions, something delivered down the genome-line.
As for us: makes sense at first. I do have to learn a lil more about our brains, that is. I'd thought that the more carnal regions are 'brain-stem upwards', the large of the cranium our pride. Perhaps one shouldn't rely too much on regional separatism within the brain - the lack of such which might show in the ease by which we so quickly and eagerly [de-]generate back into carnal reacting.

Moeee...

May. 06 2014 02:17 PM
nor

We get phenological changes within a generation or two in newly domesticated animals too. It would be interesting to see if brain mass loss occurs in wild animals taken captive (like orcas). This includes brain mass loss, which continues until it bottoms out. It doesn't even require any human contact for this to occur - wild animals kept in fenced in areas experience it as well, even on game preserves. It is also heritable and irreversible. We lost the last true wild horse long ago - those wild in the West for the past 600 years haven't recovered, the takhi in the East are not what they were either, and we don't know what we've lost of them. I'd like to know if it is the uterine environment, or that plus epigenetic changes which seems likely, also if it is heritable through the male parent, which is also likely.

May. 06 2014 01:47 PM
Alissa

The science part is, of course, interesting but really, I just liked listening to the sheep chant.

May. 06 2014 12:02 PM
Person

This audio sounds like a mob of ewes calling to their lambs (such as will happen when lambs have been temporarily sorted off from their mothers for vaccinating, etc.)

May. 06 2014 11:56 AM
Daniel from Minnesota

An important factor that you left out is the nature of the domesticated animal's environment, which is controlled. The reason a domesticated animal has a smaller brain is because the animal isn't going to have the same variety of experiences as they would in the wild. The less variety you have, the less you're brain needs to work.

May. 06 2014 11:54 AM
Mili from Minnesota!

Best video ever.

I am in trouble. Now I want a sheep

May. 06 2014 11:22 AM

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