Animals in Translation

Temple's advice on Labrador retrievers

2006-04-05T06:47:00.000-07:00

There are two kinds of Labs, big-boned service Labs and slender, hyper Labs who would go crazy lying next to a wheelchair all day long. If you want a Labrador retriever who's calm, you have to find a service-type Lab. If you like hyper dogs (a hyper Lab can be a lot of fun) then choose a Lab who wouldn't be a candidate for service training.

When I was a child we had two black Labradors in our neighborhood, Hunter (a boy) and Tucky (a girl). Tucky was active and slender, and all she wanted to do was have kids throw the ball for her. She had this spit-covered tennis ball, and she'd just keep bringing the ball to you and dropping it. If you were bored and didn't want to throw the ball any more, she'd pick it up and drop it again, then keep doing it until you finally gave in and threw the ball. She'd pick it up and drop it, pick it up and drop it, pick it up and drop it. She could do this all day long.

Hunter was heavy-boned, heavy-bodied, and thick, and he could care less about the ball. Very, very friendly, very good with the kids. But he wasn’t active. Hunter was perfectly content to just lie around.

Hunter is the kind of dog you would use for a service dog, because he’s calm. He can lie around and not do very much all day long. Tucky would have gone crazy if she’d had to stay by a wheelchair all day.

posted by Catherine for Temple Grandin

laughing dogs and other animals

2006-04-05T05:37:00.000-07:00

If you asked people who live with dogs whether dogs laugh, probably most would say 'Sure.'

Now scientists may be confirming folk wisdom where dogs are concerned:

To an untrained human ear, it sounds much like a pant, 'hhuh, hhuh,'" says Patricia Simonet of Sierra Nevada College in Lake Tahoe. However, this exhalation bursts into a broader range of frequencies than does regular dog panting, Simonet discovered when she and her students analyzed recordings.

They observed the bursts during play but not in aggressive clashes, Simonet reported in Corvallis, Ore., last week at a meeting of the Animal Behavior Society.

Gordon Burghardt of the University of Tennessee in Knoxville, who theorizes about the evolution of play, says Simonet's presentation caught his interest. Her dog-laughing proposal needs more testing, he cautions. But he notes that other scientists have proposed that nonhuman primates and even rodents laugh.

[snip]

With recordings of such laughs and growls, the researchers tested 15 mostly young dogs in an observation room. When the researchers broadcast the laugh, a puppy often picked up a toy or trotted toward a presumed playmate, if a person or another dog was in the room. Simonet's own best attempt at the laugh likewise prompted dogs to look for a romp. Broadcasting growls elicited no such effects.

Rats probably laugh, too:

This dog-exhalation study reopens many questions about whether animals laugh, comments Brian Knutson of the National Institutes of Health in Bethesda, Md. He has recorded chirps that laboratory rats give as they wrestle with each other. Rats also chirp before receiving morphine or having sex. He interprets the sound as indicating "the rat expects something rewarding."

illustration: Dogs at play give breathy exhalation (top) that differs from standard pants (bottom, arrows).
photo: Simonet
further reading:
2000. The Smile of a Dolphin: Remarkable Accounts of Animal Emotions. Bekoff, M., ed. Random House/Discovery Books.
Provine, R.R. 2000. Laughter: A Scientific Investigation. Viking: New York.

source:
Don't look now, but is that dog laughing?
Science News
week of July 28, 2001
Vol. 160, No. 4, p. 55

Malcolm Gladwell on pit bulls

2006-01-30T18:31:00.000-08:00

Malcolm Gladwell has an article out on the difficulties involved in profiling pit bulls (and criminals).

Excerpt:

The goal of pit-bull bans, obviously, isn’t to prohibit dogs that look like pit bulls. The pit-bull appearance is a proxy for the pit-bull temperament—for some trait that these dogs share. But “pit bullness” turns out to be elusive as well. The supposedly troublesome characteristics of the pit-bull type—its gameness, its determination, its insensitivity to pain—are chiefly directed toward other dogs. Pit bulls were not bred to fight humans. On the contrary: a dog that went after spectators, or its handler, or the trainer, or any of the other people involved in making a dogfighting dog a good dogfighter was usually put down. (The rule in the pit-bull world was “Man-eaters die.”)

[ed.: This is an example of what Temple calls 'informal selection pressures,' or culling.]

A Georgia-based group called the American Temperament Test Society has put twenty-five thousand dogs through a ten-part standardized drill designed to assess a dog’s stability, shyness, aggressiveness, and friendliness in the company of people. A handler takes a dog on a six-foot lead and judges its reaction to stimuli such as gunshots, an umbrella opening, and a weirdly dressed stranger approaching in a threatening way. Eighty-four per cent of the pit bulls that have been given the test have passed, which ranks pit bulls ahead of beagles, Airedales, bearded collies, and all but one variety of dachshund. “We have tested somewhere around a thousand pit-bull-type dogs,” Carl Herkstroeter, the president of the A.T.T.S., says. “I’ve tested half of them. And of the number I’ve tested I have disqualified one pit bull because of aggressive tendencies. They have done extremely well. They have a good temperament. They are very good with children.” It can even be argued that the same traits that make the pit bull so aggressive toward other dogs are what make it so nice to humans. “There are a lot of pit bulls these days who are licensed therapy dogs,” the writer Vicki Hearne points out. “Their stability and resoluteness make them excellent for work with people who might not like a more bouncy, flibbertigibbet sort of dog. When pit bulls set out to provide comfort, they are as resolute as they are when they fight, but what they are resolute about is being gentle. And, because they are fearless, they can be gentle with anybody.”

Then which are the pit bulls that get into trouble? “The ones that the legislation is geared toward have aggressive tendencies that are either bred in by the breeder, trained in by the trainer, or reinforced in by the owner,” Herkstroeter says. A mean pit bull is a dog that has been turned mean, by selective breeding, by being cross-bred with a bigger, human-aggressive breed like German shepherds or Rottweilers, or by being conditioned in such a way that it begins to express hostility to human beings. A pit bull is dangerous to people, then, not to the extent that it expresses its essential pit bullness but to the extent that it deviates from it.

Catherine speaking: over Christmas vacation, we visited Bob B., who is one of our best friends in Los Angeles. Bob and his family have become devoted lovers of pit bulls - they have 3 of them!

Having met those dogs, we've become pit bull devotees, too. They are incredible dogs, astonishingly focused on humans. Vicki Hearne is right: the dogs we met were fearless, resolute, and gentle.

Unfortunately, given the fact that criminal breeders are now deliberately mixing dog-aggressive pit bulls with human-aggressive breeds like the Akita, I'd be too nervous to buy or rescue a pit bull myself. I wouldn't feel confident that we'd be able to know what kind of genetic mix we were getting. We have 3 kids, two of them with autism; plus we have lots of kids coming to the house; and we have lots of neighborhood dogs walking by. Bob lives in Topanga Canyon where he can keep his dogs separate from other people and other dogs.

So we're going to be living a pit bull-free life for the foreseeable future.

But these are incredible animals.

source:
The New Yorker
Issue of 2006-02-06
Posted 2006-01-30

books by Vicki Hearne:
Bandit: Dossier of a Dangerous Dog
Adam's Task: Calling Animals by Name

about Vicki Hearne:
Vicki Hearne, Animal Trainer and Philosopher

safe roads for animals

2005-12-23T18:53:00.000-08:00

TUCSON, ARIZ. - A stream of traffic flows along Picture Rocks Road, past two roadside culverts where Natasha Kline is checking for animal tracks. The tunnels, intended to drain a sandy wash, are serving instead as life-saving byways for wildlife along this busy commuter route through Saguaro National Park.

As a park biologist, Ms. Kline knows such crossings can be crucial. A recent study counted as many as 53,000 animals killed on Saguaro's roads each year. "It's a huge problem," she says, "and our issue will be every park's issue in 10 years or so."

[snip]

Increased roadkill in national parks and on America's roads is a serious issue. About 275,000 animal-related crashes occur each year in the US, according to the National Highway Traffic Safety Administration. An estimated 1 million animals are killed on America's roads each day.

Scientists and transportation planners are seeking to reverse the trend.

[snip]

"The first step is understanding where the wildlife passages and corridors are," says Alison Berry, director of the Road Ecology Center at the University of California at Davis. "Then you can go on to [developing] structural barriers, various kinds of underpasses or culverts, and wildlife crossing structures."

Here in Westchester County, deer-car crashes are a danger. Last summer a deer jumped the stone wall at the bottom of our road and landed in the path of a car doing 40 mph.

I happened to be walking home with my neighbor at the time, and when we reached the car, we found the driver sitting inside crying. The deer lay in the road, dead. Terrible.

Culverts like the one in the photograph are one solution.

source:
A push for animal-friendly roads: In road ecology, transportation engineers and biologists cooperate on projects so fewer animals are struck by cars.
By Tim Vanderpool
December 20, 2005 edition
Christian Science Monitor

can bees tell people apart?

2005-12-12T17:13:00.000-08:00

Yes.

SCIENCE NEWS reports on new research by Adrian Dyer of Johannes Gutenberg University in Mainz, Germany.

Dyer, who studies bee and human vision, wondered whether an animal that had faced no evolutionary pressure to distinguish among people could recognize human faces. "I thought it was a long shot," he says.

He and his colleagues fastened a portrait above each of four feeders that dispensed either a bee-favorite sugar solution or a solution tainted with quinine, which bees disdain. The researchers borrowed some black-and-white portraits of men's faces from a standard test used to diagnose people with cognitive deficits.

The researchers put the bees through a multistep education in picking out a photo of a beardless young man. They put his picture above two of the sugar feeders and placed images of another face above the two quinine feeders. Between trials, the researchers shuffled the positions of the pictures and the solutions, keeping the sweet flavor with the one man's photo.
After one trial with a stylized face and another with an unfamiliar photo above the quinine solution, a bee had learned to fly to the first man's photo most of the time. The researchers then switched the unfamiliar photos, emptied all the feeders, and positioned the photos. As long as the photos were upright, the bees picked out the original fellow's face at least 80 percent of the time.

I'm not surprised by this, given research showing that bees have better working memory than researchers had thought.

The big question is whether bees can tell distinguish among photos of the same person with different facial expressions.

source:
Face Time: Bees can tell apart human portraits
Week of Dec. 3, 2005; Vol. 168, No. 23 , p. 360

danger mouse

2005-12-12T15:04:00.000-08:00

Temple called to point me to two new articles in Science News , one on the 'danger mouse,' and one on bees.

Here's the mouse:

By removing one gene from a mouse's standard repertoire, scientists have turned a timid animal into an intrepid one.

Gleb Shumyatsky of Rutgers University in Piscataway, N.J., and his colleagues study the genetics that affect how animals remember scary stimuli and how they respond to fright. "Fear is definitely important when you think about the survival of an organism," Shumyatsky says. "If you make a single mistake, you can be eaten or killed."

In 2002, Shumyatsky and his team discovered that the amygdala, which processes fear, has high levels of a protein called stathmin.

So they bred a knock-out mouse lacking the gene that directs the production of stathmin.

Then they looked at two kinds of fear:

innate fear (heights, predators)
learned fear (such as a tone that signals a shock)

The stathmin-free mice were far less fearful:

When normal mice are released into a new cage, they skulk near the edges. A hardwired fear of possible predators seems to keep the animals from immediately exploring their environment. Shumyatsky and his colleagues found that mice missing stathmin strolled into the middle of new cages sooner than normal mice did. In another experiment, stathmin-free mice spent more time than normal mice did on platforms set up 50 centimeters above the floor.

Standing up high on a platform is something dogs and cats do, not mice.

The knock-out mice were less troubled by learned fears, too:

Shumyatsky and his team taught groups of mice to expect a mild shock after hearing a loud tone. Normal mice froze in place for several seconds whenever they heard the tone, even if the shock didn't come. Although stathminfree mice also struck a pose at the sound of the tone, they held it only 60 percent as long as the normal mice did.

Nothing else seems to have been affected. The knockout mice looked normal in memory, hearing, and pain perception—and they did have some fear: "They weren't stupid," Shumyatsky told SCIENCE NEWS. "If you wanted to catch them, they ran away."

However, other areas of the brain produce stathmin as well, so it's reasonable to assume that it's involved in other behaviors, too, as Joseph LeDoux of NYU points out.

I'll be interested to see what other behaviors stathmin might affect.

source:

Danger Mouse: Deleting a gene transforms timid rodents into daredevils

Week of Nov. 26, 2005; Vol. 168, No. 22 , p. 341

Heart of the Horse

2005-11-28T10:22:00.000-08:00

Just spoke to Temple—she is raving about Heart of the Horse, a book of photographs by Juliet Van Otteren. Text by Alan Lightman, foreword by Jane Goodall.

The cover photo is exquisite.

Juliet Van Otteren's website is here.

that's why they call it the pecking order

2005-11-24T20:49:00.000-08:00

The Wall Street Journal has a story on aggressive tom turkeys:

In April, Will Millington was riding his dirt bike down a narrow trail in Norman, Okla., when he stopped before a flock of wild turkeys. The hens scattered, but two toms flared their feathers and stalked toward him. Then they suddenly leapt in the air, beat Mr. Millington with their wings and tried to scratch him with the sharp spurs on the backs of their legs.

Mr. Millington frantically revved his bike's motor. Thirty yards down the trail he looked back. "They were running after me," says the 46-year-old property manager. "That was kind of spooky."

[snip]

...naturalists who have studied the wild turkey say it can become aggressive toward humans as it adapts to suburban life. They worry it may become the next form of "nuisance" wildlife, following in the tracks of the whitetail deer and the Canada goose.

Wild-turkey flocks have a pecking order. If they live around humans, some of the dominant toms may begin to include people in that order -- at a level below themselves, says Jim Cardoza, a turkey expert at the Massachusetts wildlife agency. Wild turkeys "get used to people and incorporate them into their view of society," he says. Some behavior, such as putting out bird food and slinking quietly away, can encourage these lordly males to think that humans are a subservient life form, believes Mr. Cardoza.

Biologist James Earl Kennamer, senior vice president of the National Wild Turkey Federation, an Edgefield, S.C., hunters' group, has studied wild turkeys for 40 years. "When they think you're one of them, they'll fight you to show who's dominant," he says. "If you turn your back, they'll take it to mean they're dominant."

[snip]

Last month, jogging on a back road in Massachusetts' Berkshire hills, Betsy Kosheff passed a farmers' field where farm-raised wild turkeys were pecking for grain. Suddenly about 30 of them took off after Ms. Kosheff, who has a public-relations firm in West Stockbridge, Mass.

"It was like that scene in 'The Birds' except there was no phone booth," says Ms. Kosheff, referring to the famous refuge in the Alfred Hitchcock movie. A passing friend stopped her pickup truck and Ms. Kosheff ran around it several times. The turkeys kept up the chase, although she says "they were too stupid to split up or change directions" to trap her. Finally, Ms. Kosheff got in the truck, where, she says, her friend "was laughing so hard she almost choked on her Dunkin' Donut."

We have very similar stories about bulls in Animals in Translation : Using the Mysteries of Autism to Decode Animal Behavior.

Lesson:

Never let a bull—or a tom turkey—think he's a person.

Happy Thanksgiving!

source:
One for 'The Birds': Wild Turkeys Attack Humans in Suburbia

In the Company of Crows and Ravens

2005-11-22T20:14:00.000-08:00

...is the title of a new book by John M. Marzhuff and Tony Angell Temple's been reading.

Terrific story:

Marzhuff and Angell watched a team of crows—possibly as many as 5—gang up on an otter with a fish.

Some of the crows would swoop in and distract the otter, poking his tail and bugging him, while the others watched and waited for their chance to snatch the fish away.

Once the watching crows got the fish, they all flew off together.

Teamwork.

birth of a new language

2005-11-14T17:11:00.000-08:00

The Economist reports that Bruno Galantucci, a cognitive scientist at Yale, has created a computer game for two that forces the players to invent a new language in order to play. The object of the game is to find each other inside an onscreen bungalow:

The two players cannot see or hear each other, but they are seated at interconnected computers. In the simplest version of the game, each player is located in one of four rooms and must find each other in one move each. These rooms are arranged in a square, and each pair of adjacent rooms is connected by a doorway. On the floor of each room is an icon—a circle, a hexagon, a flower—and, prior to the game starting, the players have a short time to explore their surroundings. (Sometimes, a player with good spatial awareness can move quickly through all four rooms and understand the layout but others do not grasp it at this stage.)

The players know there is another player in another of the rooms, and that they must both end up in the same room, but they can only ever see the room they are in. To help them guide each other to a rendezvous, they have a device on which they can scrawl symbols that appear on the other's screen. But the device works like a roll of paper that constantly scrolls downwards, preventing them from writing letters, numbers or any other commonly recognisable symbol.To communicate, the players have to invent new symbols.

The amazing thing is, they can do it. 9 of 10 pairs found each other onscreen in 3 hours, after inventing 3 or 4 shared symbols. Some pairs found each other in minutes; some took hours. A few never found each other at all.

The fascinating aspect of this research, from the perspective of the problems autistic people have with language, is that imitation is key to developing a successful new form of communication:

Having observed winning pairs at play, Dr Galantucci says that communication is established as soon as one player decides to copy the symbols proposed by his co-player, rather than impose his own. At that point the pair's chances of finding each other jump. As soon as there is imitation, he says, there is a common currency. After that, it is relatively easy to attach useful information to those symbols.

And listen to this:

"What is striking, he says, is that a pair can be successful even if a symbol represents something quite different in the virtual world to each player—as long as they agree on what they should do when confronted by it. In other words, people only need to convey a small amount of information to communicate effectively, and they can do so while holding fundamentally different ideas about how their language describes the world."

This is amazing.

"Communication" works just fine when very little is actually being communicated.

What matters is behavior, not thoughts.

If you're doing what you should do when you see or hear a symbol, it doesn't matter whether you understand what the other person means by the symbol.

For two people to communicate, they just need to agree on the actions they want each other to take, not the meaning of the actions!

Looks like the behaviorists were right.

source:
"Looking for a sign," THE ECONOMIST, November 10, 2005

mouse song

2005-11-10T18:20:00.000-08:00

I'm talking to Temple on the phone right now; she's fascinated by the new research showing that mice can (probably) sing. It's further support for her feeling that music is the language of animals.

Here's what else she has to say:

"The only social cue I could understand was tone. I used to call up clients just so I could hear their voice. If I thought a client was annoyed with me, I would call them up just to see if I could hear this little annoyed whine in their voice. I could tell by their voice that they were annoyed. I could also tell by their voice if they were happy!"

"I could never understand for the longest time why people wanted to meet each other in person. I thought it was enough just to meet people on the phone, because all I needed to do was hear their voice. Meeting them on the phone was as good as meeting them face to face, because at that point I didn't even know eye signals existed."

"I did not know that eye signals existed until I was 50. I read about them in Simon Baron-Cohen's book Mind Blindness: An Essay on Autism and Theory of Mind. That's how I found out they existed."

Here's The Economist's description of the new research on singing mice (subscription required) :

Timothy Holy and Zhongsheng Guo of the Washington University in St Louis, Missouri, made the discovery after studying how male mice respond to female mouse pheromones, the chemical signals linked, among other things, to mating. The mice made noises inaudible to the human ear, and the researchers recorded and analysed them.

By dropping the pitch of the recordings so that humans could hear it, the researchers found that it sounded remarkably like birdsong. Each mouse made a series of “chirps” with bursts of closely spaced notes interspersed with lulls. Details were published this week in the Public Library of Science Biology.

To be classified as a song, a vocalisation has to contain distinct notes, rather than one sound repeated, as well as motifs and themes that recur from time to time. The researchers identified distinct clusters of pitch changes in the songs by analysing a set of 750 syllables produced by one mouse in a single 210-second recording. They concluded that these pitch changes followed a pattern and were thus a song. Tests with 45 different mice produced similar results, although each mouse had its distinct chanson.

sources:
Beyond Falsetto
Melodic Mice

are bees as smart as pigeons and monkeys?

2005-11-09T14:44:00.000-08:00

They might be, if working memory is as important to general intelligence as it appears to be.

Working memory is the faculty we use to remember a phone number while we're dialing it—or to remember the beginning of this sentence while reading to the end.

Some brain scan research suggests that working memory and "general fluid intelligence" are strongly correlated. A difference in IQ probably means a difference in working memory, and vice versa.

Getting back to bees, when Shaowu Zhang and his colleagues tested honeybees' working memory, they found it lasted about 5 seconds—same as a pigeon's. Moreover, according to Zhang "a honeybee's memory is flexible enough to perform a simplified version of a task employed to test memory in rhesus monkeys."

Zhang calls the working memory of bees "robust and flexible."

If working memory is part of general intelligence, and honeybees have working memories as good as those of pigeons and monkeys, there's no reason to assume pigeons and monkeys are a lot smarter than honeybees.

sources:
Little Brains That Could: Bees show big-time working memory
Visual working memory in decision making by honey bees
The General Intelligence Factor
Study links problem-solving skills to brain 'g' spot

Labs are number 1

2005-07-11T09:42:00.002-07:00

Labrador retrievers have been the number one dog in America for 12 years.

Labs are so popular that there are 3 times as many of them as golden retrievers, the number 2 dog on the AKC's list of registered breeds

Before Labs reached the top, cocker spaniels were number 1 for 8 years, and before that poodles were the most popular dog in America for 25 years.

Top Dog: Why Americans love Labrador retrievers by Brendan Koerner

more on mama dolphins

2005-07-08T19:56:00.000-07:00

As usual, Temple knew exactly what to think about the mama dolphin and her sponge-fishing' technique.

She said the dolphin was protecting her nose from stingrays that hide flat on the bottom of the ocean, hidden in the sand.

Temple has seen footage of a dolphin that died after being stabbed by a stingray.

Temple figured this out instantly, as soon as she read the new research on dolphins with sponges on their noses. The image of a hidden stingray ambushing a dolphin popped into her mind's eye:

"I'm visualizing that now," she said. "Having that sponge to protect its nose is really important. A stingray wouldn’t go through the sponge."

Temple was also struck by the fact that all of the dolphins using the sponges were genetically related.

"One real clever individual started it," she said.

Kitchen Table Math

2005-06-26T15:19:00.000-07:00

I've posted links to Temple's web site & to my own web site on the subject of teaching math to children, which I write with Carolyn Johnston.

Carolyn has a Ph.D. in math, and you can read about her work at Kitchen Table Math&mdash

mama dolphins teach their babies

2005-06-08T14:53:00.000-07:00

Animal researchers keep trying to find something that sets people apart from animals.

Usually people think language is the big divide, but they've also talked about other differences.

Some researchers have been thinking about whether animals have cultural evolution. Cultural evolution means that one generation passes its knowledge on to the next generation; then the next generation adds more knowledge to it & passes the old knowledge along with the new knowledge on to its children.

Humans invented the wheel, then they invented steam engines so they could have trains, then they invented gas engines so they could have cars ...that's cultural evolution.

People don't have to 'reinvent the wheel' each generation. Their parents or teachers tell them how to make a wheel, so they have the time to make something new.

Today most researchers believe that some animals do have their own unique cultures. The adults in the group can learn from each other through observational learning, and parents teach skills to their babies.

Also, one group of animals can have skills that a neighboring group doesn't have.

That's culture.

But researchers don't believe animals have cultures that are evolving over time the way ours is.

Now even that difference between humans and animals may not be holding up.

I can't tell from this report whether these 'sponge dolphins' have cultural evolution, or whether this is a case of social learning between two generations.

So I'm going to be following these reports:

A group of dolphins living off the coast of Australia apparently teach their offspring to protect their snouts with sponges while foraging for food in the sea floor. Researchers say it appears to be a cultural behavior passed on from mother to daughter, a first for animals of this type, although such learning has been seen in other species.

The dolphins, living in Shark Bay, Western Australia, use conically shaped whole sponges that they tear off the bottom, said Michael Kruetzen, lead author of a report on the dolphins in Tuesday's issue of Proceedings of the National Academy of Science.

''Cultural evolution, including tool use, is not only found in humans and our closest relatives, the primates, but also in animals that are evolutionally quite distant from us. This convergent evolution is what is so fascinating,'' said Kruetzen.
Researchers suspect the sponges help the foraging dolphins avoid getting stung by stonefish and other critters that hide in the sandy sea bottom, just as a gardener might wear gloves to protect the hands.

[UPDATE: I've added some notes from Temple more on mama dolphins]

capuchin monkeys buy Jell-o

2005-06-07T17:49:00.000-07:00

Steven D. Levitt and Steven J. Dubner have written their first Freakonomics column for the New York Times about some 'economics' research on capuchin monkeys:

''The capuchin has a small brain, and it's pretty much focused on food and sex,'' says Keith Chen, a Yale economist who, along with Laurie Santos, a psychologist, is exploiting these natural desires -- well, the desire for food at least -- to teach the capuchins to buy grapes, apples and Jell-O. ''You should really think of a capuchin as a bottomless stomach of want,'' Chen says. ''You can feed them marshmallows all day, they'll throw up and then come back for more.''

Dr. Santos thinks the monkeys understand the meaning of money because of a couple of 'bank robberies' she's seen:

All seven monkeys live in a communal main chamber of about 750 cubic feet. For experiments, one capuchin at a time is let into a smaller testing chamber next door. Once, a capuchin in the testing chamber picked up an entire tray of tokens, flung them into the main chamber and then scurried in after them -- a combination jailbreak and bank heist -- which led to a chaotic scene in which the human researchers had to rush into the main chamber and offer food bribes for the tokens, a reinforcement that in effect encouraged more stealing.

The researchers saw something else, too, that I won't put on a family blog. Grownups might want to go read the article, though.

There are some really nice photos here.