Reconnect With Nature Blog

As Below, So Above

For several days now, as I have been taking my dog for a walk around a pond at the local state park, I have been assaulted by a deer fly (family Tabanidae). The fly always starts buzzing me in the same 30 meter (100 feet) stretch of path, where the acacia trees provide some shade and the winds blow gentle puffs of air.

The fly seems to have a very circumscribed territory. Once I get out of that 30 meter stretch, he breaks off his attack and disappears, only to reappear during my next circuit on that path.

I try to put myself into the world of this fly. I am guessing that his world is encompassed in a plot of land that has a diameter of 30 meters. This is all that he knows. This is all that he sees. At random unpredictable times, potential meals move into range, triggering a hunger response. Outside that range, potential meals vanish, as if they never existed.

With my superior vision, I can see the whole pond, and I can think that it is very quaint that the fly cannot realize that simply going outside his 30 meters would give him more potential meals. He is limited by his perception, in ways that I am not.

But then I think, how much are we humans limited by our perception? Many years ago, I met a farmer who had not traveled more than 20 kilometers (12 miles) from where he had been born 70 years previously. Now many of us travel around the globe fairly effortlessly, and we can use electronic means of perception to see what is happening anywhere in the world.

But our solar system is huge, our galaxy is larger, and our universe is larger still. We can’t see anything of what is happening there, with a few paltry exceptions of Hubbell telescopes and rockets sent to other planets.

Like the fly, our world is circumscribed. We can see much more than the fly, but in the larger scheme of things, our perception does not extend out much more than his, in terms of cosmic distance.

To paraphrase a Hermetic saying, “As below, so above.”  We and the fly have much in common. We both can only see a very small portion of reality. And as we delve into quantum physics, we are not very sure what really is reality. Perhaps there are intelligences greater than ours who think that it is very quaint that we cannot realize that by simply going beyond the limits of our current perception we can see a greater reality. Or perhaps not.

I don’t know if the fly worries about such questions. Current scientific thought would suggest that he is not capable of such thoughts.  And perhaps we too are not capable of thoughts that would transcend our reality, allowing us to see a larger world.

So what to do? In my case, I am simply going to enjoy my moment in Nature, and even though the fly wants to suck my blood, I am going to enjoy his buzzing, even as I wait for my steps to take me out of his range.

Groundhog Day 365

February 2 was Groundhog Day, when Groundhog Chuck bit Mayor Michael Bloomberg in New York and Punxsutawney Phil saw his shadow in Pennsylvania. Groundhog Day is also immortalized in the film of the same name, where Bill Murray is doomed to repeat the day over and over again until he emerges as a kinder and gentler person.

In the West, some organizations such as the Prairie Dog Coalition and WildEarth Guardians celebrated the day as Prairie Dog Day, in honor of the iconic symbol of the western grasslands and plains. As I was preparing to attend a Prairie Dog Day celebration sponsored by the Denver Zoo, a person asked me: “Groundhogs and prairie dogs do something for people one day of the year. What do they do for us the rest of the time?”

On one level, this question has an easy answer. Prairie dogs and groundhogs dig into the soil, creating in the case of prairie dogs extensive burrow systems. The burrowing helps bring up to the surface nutrients that are locked in the ground, allowing those nutrients to be used by plants on the prairies. The burrows also allow rainwater to percolate into the ground, helping to recharge the aquifers on which we all depend for the water we drink.

Prairie dogs serve as keystone species in grassland ecosystems, helping to support a large web of predators, herbivores, and detritivores that depend to a large extent on the burrows for shelter, the plants that grow in prairie dog towns and the prairie dogs themselves for their daily food. If we eliminate these keystone animals, we have no idea what that is going to do to the energy flowing through grassland ecosystems. Certainly the populations of other species will crash, and it is very likely that a number of other species will go extinct.

The grasslands that prairie dogs live in make up about 40-50 percent of the land surface of the United States. These grasslands, and all the species of plants and animals that live there, provide a number of important ecosystem services, such as sequestering carbon and nitrogen, controlling erosion, and facilitating the percolation of water through the soil. On an economic scale, my coauthors and I estimate in our newly-released book, Prairie Dogs, that these ecosystem services bring in between $275 to $539 per hectare (about 2.5 acres) into our economy. As keystone species, prairie dogs play a major role in maintaining the ecological health of the grasslands.

On another level, however, the question of what groundhogs and prairie dogs do for us has a much more difficult answer. We humans tend to have an anthropocentric view of the world, seeing everything from our own perspective. Many times, that perspective does not see the value of the plants and animals that share our world. For example, prairie dogs have declined to about 2 percent of the population size they had 100 years ago, largely due to human actions and activities. As such, they join the 20 percent of mammalian species around the world that are heading toward extinction. From a self-interest standpoint, we should be concerned about this. Ecological studies have shown us that there is a delicate balance between all of the organisms living within an ecosystem. Perturbations that lead to disturbances of the energy flowing through a ecosystem, as well as changes in hydrologic, nitrogen, and carbon cycles, can lead to instabilities that are difficult to predict. We know that eliminating prairie dogs from grasslands can lead to higher local surface temperatures. As with the “Butterfly Effect,” can it also lead to greater climatic instability in our western plains states? The short answer is, we don’t know.

Yet we persist with our activities as if we knew all the answers, and like Bill Murray’s character in “Groundhog Day,” we do not seem to learn much day after day as species after species goes extinct. There is hope, however. In the end, Bill Murray’s character started to learn about the value of becoming a kinder, gentler person. We too should learn that there is value in all the living organisms that inhabit this earth, and treating them with gentle kindness all 365 days of each year might help our long-term survival on this planet.

Con Slobodchikoff, together with Bianca Perla and Jennifer Verdolin, are authors of the book Prairie Dogs: Communication and Community in an Animal Society, newly-released on February 2, 2009 by Harvard University Press.

 

 

 

 

 

A Conversation On Anecdotal Evidence

This is an email conversation between Randall Johnson and Con Slobodchikoff on the value of anecdotal evidence in biology.

Randall Johnson:
I've submitted a new Dog Behavior Blog comment (http://www/dogbehaviorblog.com) in response to your latest entry, "A Dog's Concern for a Cat". Focus: anecdotal evidence as a useful source of information.

Comment on Dog Behavior Blog: This incident joins a long list of other reported observations that clearly show that dogs are capable of feelings we associate with empathy and sympathy and that they extend these feelings toward other species.  If we had only a handful of stories like this one, then we could say this is anecdotal evidence, but when there are hundreds of stories reporting similar behavior, we no longer have anecdotal evidence, but rather a solid body of observational evidence. Since the human environment is the dog’s natural habitat, then these reports can also be considered as field observations, which is a respected source of data-gathering. I don’t know if anyone has decided how many anecdotes it takes to cross over to the realm of observational field data, but if this hasn’t been done yet, it’s high time some kind of marker was devised. And, in defense of anecdotal evidence, Hungarian ethologist Vilmos Csányi of the Eötvös Loránd University, who has devoted more than a decade to investigating dogs’ cognitive abilities, has used anecdotes on many occasions to inspire more formal experimental investigations.

Con Slobodchikoff:
Thank you for your insightful comment, which I published on the dog behavior blog.  As you know, "anecdotal evidence" can sometimes be used as a convenient way to sweep inconvenient evidence under the proverbial rug. There surely has to be some kind of standard for how much anecdotal evidence constitutes proof, but I don't know of any standards. However, if you go back to the papers in biology journals of 60-70 years ago, much of what was presented there was in the form of anecdotal evidence. Where would science be today if we discounted such evidence?

Randall Johnson:
While writing my comment, I was pretty sure there was no standard for anecdotal evidence. You raised a good point about this kind of evidence having played an honorable role in science in the past.
Somewhere along the way, it was stripped of some of its original credibility and we need to get it back or devise some clear guidelines for its use as a source of evidence.

I am submitting a brief comment in response to the "Are We Unique?" essay on the Reconnect With Nature blog. (I'm surprised this one hasn't generated more responses.)

Con Slobodchikoff:
First, thanks for your comment on Are We Unique. As usual, a great comment! I have posted it, and I hope that it raises some discussion or at least some thoughts on the part of the readers.

For the anecdotal evidence part, it seems to me that biologists have bought into the idea that experimentation is the only way to obtain valid biological data. This is fine for lab studies, but experiments are often difficult to do in nature, under field conditions, and a lot of the time we are left with observations that cannot be quantified or even repeated. In my mind, this does not make them any the less valid. I think we need to come back to a point where a certain quantity of similar observations is accepted as proof of the validity of a particular behavior or biological circumstance.

Randall Johnson:
My question, at the beginning of this discussion, was: At what point does an observed behavior stop being treated as anecdotal evidence and be recognized as observational data? Most definitions I’ve looked at stated that anecdotal evidence is limited to one or a small number of cases, but no one, so far, has said, “Well, if you have 10 cases of “X” behavior, it’s anecdotal, but if you have 11 cases, it’s observational data.” Maybe it’s not all that important, but considering science strives for precision, there’s a big fuzzy area here that’s calling out for better definition.

However, the larger issue is still related to the credibility of anecdotal evidence. In the late 19th century, it fell under some heavy criticism, largely because George Romanes, Charles Darwin’s protégé and an eminent biologist in his own right, relied heavily on anecdotal methodology to develop his theory of comparative psychology and, to this day, there still seems to be a lingering ‘cloud of doubt’ hanging over it.

Then, the other day, I came across a news item from 2005 on the Science Week web site that I found particularly insightful. In discussing numbers and counting in chimpanzees, the writer pointed out that one problem with investigating non-human primates is that experiments can’t be done on large populations because such populations either don’t exist or are prohibitively expensive to maintain. The result is that reported experiments are often "anecdotal", i.e., experiments involving only a few or even a single animal subject. The writer then stated: “But anecdotal evidence can often be of great significance and have startling implications: a report, even in a single animal, of important abstract abilities, numeric or conceptual, is worthy of attention, if only because it may destroy old myths and point to new directions in methodology.”

The debate continues. Although I’m not a gambling man myself, I’m willing to bet that, in the end, anecdotal evidence will regain its former luster and that the academic / scientific community will universally recognize it as a valid—and valuable—source of data. Let’s face it. There are still lots of old myths out waiting to be slain.

Con Slobodchikoff:
Yes, it is true that many experiments cannot be done on multiple animals because of the cost or the lack of animals. I was talking just the other day to someone about Alex, the parrot (see earlier post: A Tribute To Washoe And Alex), and the person I was talking to pointed out that we can’t generalize from only one parrot to say that parrots might have language-like abilities or the cognitive skills to count and identify colors and shapes: Alex might have been a genius among parrots, a feathered Einstein. That might very well be true, and Irene Pepperberg is doing careful experiments with other parrots to test for this possibility. However, Pepperberg’s extensive experiments with Alex show that not all parrots are incapable of complex cognitive skills.

Unlike Pepperberg’s work with Alex, many observations cannot be repeated on command. Does that invalidate them? I guess it depends on the credibility of the observer and the relative novelty of the observation.  If I say that I saw my dog burying a bone in my back yard, no one would question this anecdotal observation. However, if I say that I saw my dog surfing the internet on my computer, lots of people would probably discount that as pure fantasy, because it does not fit the current dogma of what dogs are capable of doing and no one else has reported this (and no, my dog does not surf the internet).

But we have to be careful about discarding observations that do not fit our preconceived notions. If an observation comes from a credible source and can be documented, then that observation can have the seeds of changing our thinking about the world around us.

As William James once said, you need only one white crow to disprove the assertion that all crows are black.

A Wasp Tale

At the beginning of summer, my wife opened up our outdoor grill, only to find that paper wasps (Polistes arizonensis) had built a nest hanging from the upper grill shelf. The nest formed a disk that was about 5 cm (about 2 inches) in diameter. She quickly closed the grill cover and came to ask me to do something about the wasps.

We did not want to kill them, so I thought that if I left the grill cover open, the heat of our summer days would drive the wasps to abandon the nest.  I opened the grill cover in the early morning, when the temperature was still cool and the wasps were not active. Since the temperature really soars during the heat of the day, I thought it would take the wasps only a few days to leave their nest.

Every day I watched them through our kitchen window to see what they would do. Rather than abandoning the nest, the wasps took their exposure to the sun in stride. During the heat of the day, they would all cluster on the underside of the nest, in the shade. As the sun started going down and the temperature started cooling off, they would crawl up to the topside of the nest and absorb some heat for the coming cooler night.

For the next month, I watched the wasps building up and maintaining their nest. The diameter of the nest is now about 13 cm (about 7 inches), and the wasps show no inclination to slow down their activity.

But now the Arizona monsoon is gathering. This is a time of violent rainstorms and thunderstorms. Each morning during the monsoon the day dawns clear and sunny, but by noon the clouds gather and the rain starts, lasting in fitful bursts of moisture through the early evening hours, and sometimes throughout the night.

I know that the rains are coming, and when they arrive, the paper construction of the wasp nest will be destroyed. Yet the wasps continue unfazed by the coming prospect of losing their nest.

I can say that the wasps are operating on sheer instinct and have no prior knowledge of the coming debacle that will engulf their home.   But then I think of how we humans do exactly the same thing, even though we supposedly are aware of the consequences. I remember watching villagers build houses of out lava on the slopes of a still-rumbling and smoking volcano in Guatemala. And I lived in San Francisco, where everyone knows that a big earthquake is going to arrive someday, but everyone hopes that it won’t be during their time.

We humans live in perilous places and we hope for the best. Perhaps the wasps are also hoping for the best. (I’m sure that some dogmatic scientists will say that wasps are not capable of hope, to which my reply is, how exactly do you know this, other than through your unverified opinion?).

But it does show that we humans and the wasps have something in common: We all are reluctant to leave behind the place that we call home.

A New View of Dog Domestication: Human-Canid Co-evolution

Note from Con Slobodchikoff: This post is written by guest commentator Randall Johnson.  Once involved in river dolphin research and preservation, Randall Johnson lives in the Brazilian state of Minas Gerais, where he works as a Portuguese-English translator. His household includes three dogs, two of which were adopted off the streets, and he's active in a local group that rescues stray dogs and works to find them good homes. For another post by Randall Johnson on a difference between wolves and dogs, see the Dog Behavior Blog at http://www.dogbehaviorblog.com

     For millions of people around the world, their dogs provide not only an important source of companionship, but also offer a daily way of reconnecting with nature, if for no other reason than they force us to get off our backsides and take them outside for a walk. The intense bond between humans and dogs is an old one, perhaps going back as far as 135,000 years, and we may well ask how it all got started.

     Although a number of theories have been advanced, Austrian ethologist Wolfgang Schleidt, a disciple of Konrad Lorenz, offers an elegant view that emphasizes companionship and cooperation over human domination (see Schleidt, W.M.and Shalter, M.D. Co-evolution of humans and canid: An alternative view of dog domestication: HOMO HOMINI LUPUS? Evolution and Cognition 9(1) 57-72, 2003.). Instead of perpetuating the traditional view that dogs are the products of our ancestors’ ingenuity, Schleidt proposes that the initial contact between humans and gray wolves—from which dogs descended—was mutual and that the impact of the wolves’ social ethics on our own may equal or surpass our impact on their having become dogs. He sees the various changes that occurred both in humans and wolves as a process of co-evolution.

     One of the most intriguing aspects of Schleidt’s scenario is that wolves had a powerful influence on the social ethics of the early human groups through a kind of ‘lupification’ of human behavior or, to put it another way, the ‘humanization of the ape’. Wolves, as pack animals, survive by cooperation and teamwork. They hunt together, raise pups together, share food, and share risks. On the other hand, the social life of chimpanzees, our closest biological relative, is opportunistic, almost Machiavellian in nature, with chimps looking out for ways to get the better of each other. If we look for the biological roots of those traits we value as being especially humane, like group loyalty and cooperation for the common good, we don’t find them in apes. Instead, we find them in the social canids, like the gray wolf.

     At some point after humankind separated from a chimpanzee-like ancestor around six million years ago and spread across Eurasia and into North America, the sociality of human groups stopped completely resembling the primate model and began reflecting elements of the canid model. Based on new paleontologic, biogeographic, and genetic evidence, Schleidt suggests that this shift coincided with the time humans came into close contact with wolves after moving into their domain. Wolves were not only top predators, but also nature’s first ‘pastoralists’, living off of vast, migrating herds of ungulates, e.g., reindeer and bison. During the last Ice Age, these human groups learned how to co-exist with wolves, adopting their pastoralist lifestyle and even some of their pack behavior (learning to cooperate as a group, share risks, extending relationships beyond immediate kinship, etc.). This was also the period during which early humans (i.e. Neanderthals) gave way to modern humans and dogs began separating from wolves.

     Of course, this is an extremely simplified version of one facet of a richly-detailed theory. For those who want to see the ‘big picture’, I urge them to visit the following site and read the full article: www.uwsp.edu/psych/s/275/science/coevolution03.pdf.

--Randall Johnson

Animal Language Institute

This week marks the opening of the online Animal Language Institute.

The Animal Language Institute (ALI) is a website designed to promote interest in animal communication research, especially where it touches upon the cognitive capabilities of animals. With the Internet extending past barriers of geography, politics, and economics, the Animal Language Institute is an ideal way to bring together researchers, students, and curious laypeople from around the world to share ideas and information that will deepen our understanding about the communication systems of other species.

The Animal Language Institute website hopes to be the most extensive and easily accessible repository of information about research into the communication and cognitive abilities of various species of animals. Towards this end, ALI is amassing a core collection of outstanding scientific papers, that will be available to any registered visitor.

The Institute website currently has four major sections: 1) A database of papers published on animal communication; 2) A listing of people who are doing important work in the field; 3) Equipment and software reviews; 4) Interactive tutorials.

ALI will maintain open access to the webpages of the Animal Language Institute for the next month, so that anyone can access any page without registering. After that, ALI will ask people to register in order to access some parts of the website. Registration is free, and can be done at any time. ALI is asking people to register so that it can keep track of how many people are using the resources of the site.

ALI’s website is: http://www.animallanguageinstitute.org. Its mission statement is expressed in detail on its home page, and all doors to other sections are currently open. Go to the website, wander around the pages, and see what you think. If you like what you see, go ahead and register so that you can continue to get access to the site.

A Tribute To Washoe And Alex

They were pioneers, and they died within a few weeks of each other. Like all pioneers, they pointed the way to new discoveries and new ways of thinking. And like all pioneers, they bore the brunt of skepticism from the naysayers, the folks who do not want our vision of the world to change.

They did not ask to be pioneers. That job was thrust on them by others. But during their lives, they showed the world a different view, a different perspective, a different reality from the comfortable one that has lasted for thousands of years.

They were Washoe the chimpanzee and Alex the parrot.

Washoe showed that a chimpanzee can learn a number of signs in American Sign Language and use those signs to communicate with people.  Not only that, but she showed that she could teach these signs to other chimps, and could communicate with other chimps, using the signs.

Alex showed that he could tell the differences between shapes and colors, and could use perfectly-enunciated words to communicate these differences to the people around him.

Washoe and Alex were both taught by careful scientists who went to great lengths to remove subjectivity from their analyses. But neither Washoe nor Alex was merely a “lab subject,” taken out just for experiments but otherwise ignored. The people around them cared deeply about their welfare.

As pioneers, both Washoe and Alex showed that animals have the cognitive capacity to use language in meaningful ways.  Because the scientists were very careful with their studies, it is difficult for the skeptics and naysayers to discount the results, although it appears to be the nature of skeptics and naysayers to keep trying.

And as pioneers, Washoe and Alex pointed the way to a different world. A world where we humans acknowledge that animals could have sentience and cognitive capacities that could include language. A world where we see animals as intelligent beings, rather than as objects that exist merely for our convenience. A world where animals are no longer considered as things to be used, but fellow creatures to be respected.

Reconnect With Nature On The Internet

     Many people these days are stuck in cities, where there is a limited amount of nature that they can see. Granted, there are still lots of spiders, insects, birds, and a few mammals that are typically found in cities, but the ambiance is not quite the same as being out in the woods or a mountain meadow in the middle of nowhere.

     Some of the flavor of being lost in nature can be captured through programs on TV. But TV provides the sights, and not the smells, the feel of the wind in your face, the taste of rain on your tongue.

     When I told my parents that I was going to spend more than half a year in Africa studying the behavior of hyraxes, my mother’s response was, why are you going there when you can see the same thing on TV?  She was right that I could see some video clips of hyraxes on TV, but she was wrong about the whole experience.

     Being in the wilds of Kenya was a completely different experience from watching it on TV.  A TV program cannot capture the different sensory inputs: the constant smell of wood smoke from cooking fires, the raucous chatter of baboons, the bell-like trumpeting of elephants, the slithering sound of black mambas on a rocky surface, the high-pitched buzz of African honeybee foragers hovering in front of your face, the cacophony of sound from the dawn chorus of birds, the roars of lions, the bellowing of hippos, the feel of Anopheles mosquitoes biting your arm. While there, I practiced the principles discussed in my website, www.reconnectwithnature.com.

     Even though these things have to be experienced in person, an alternative is to read nature blogs on the internet. Although the blogs cannot provide the sensory input, they can provide some commentary that gives a sense of what a place is like, or a sense of what some animals are doing.

     Two of my favorite nature blogs are Camera Trap Codger and BunyipCo. Camera Trap Codger is a blog written by Chris Wemmer, who is an eminent conservation biologist. Wemmer uses a camera trap to photograph a variety of animals in the foothills of the California Sierra Nevada mountains, and discusses the habits of the animals and the general environment. A recent post comments on the smoke from a nearby wildfire, and the memories that the smoke evokes of previous places visited around the world by Wemmer. BunyipCo is a blog written by Dave Rentz, an eminent orthopterist. Rentz lives in the rainforest of Queensland, Australia, and discusses some of the animals that can be found in the immediate vicinity. A recent post discusses the sounds made by the call of the Australian Riflebird and by the feathers as the bird flies.

     Both blogs present a flavor of what it is like to be with nature. They present the sights and sounds and feelings of the places that are discussed.

     If you feel that you need to get out into nature, you can’t go wrong by getting out into nature through either of these blogs.

Living Harmoniously

For the past two years, I have been greeting a house spider (Kukulcania arizonica) who has been living in my garage. She has taken up residence in a crack in the frame of the door leading into the house, and every evening as I go into the garage to get a can of food for my dog, I say “Hi Spider!” She usually responds by scuttling away into her crack, probably because of the vibrations of my voice on her web.

Sometimes, however, when she has caught something, she sits on her web eating, oblivious to my presence. Then I can crouch down to within a few centimeters of her and study her in detail. She is a satiny black, with long legs and a somewhat bulbous abdomen. Although she usually comes out only at night, when she is lost in her food she can keep feeding into the daylight hours, engrossed in sucking out every last scrap of fluid as if she did not know where her next meal was coming from.

The last winter was pretty cold in the garage, and I would see her sitting on her web night after night, waiting patiently for some unwary insect to stumble in. But there were no insects out in the cold. She seemed to shrink in size as the months passed, causing us to worry about her. I thought of trying to feed her, but then decided that I should let nature take its course and let her survive by her own efforts. Fortunately, she made it. Now that it is summer, insects are in plentiful supply, and many evenings I see her munching on a cricket or a beetle that she has snared in her web.

She is the longest animal resident that I know about, but there are many other animals who share our house. Little black ants (Monomorium minimum) have a nest somewhere underneath the foundation, and occasionally make their unwelcome presence known by marching in long columns through the kitchen in search of food when there is nothing to eat outside. Tree Lizards (Urosaurus ornatus) run around on the outside walls, retreating into crevices and spaces under the roof as the cold of winter sets in. An Ash-Throated Flycatcher family (Myiarchus cinerascens) nests in a hole under the eaves, with the parents faithfully bringing back an astounding number of insects for the hungry nestlings. Paper wasps (Polistes) have nests in places where the eaves have slightly come apart. I am sure that there is a plethora of other animals who live in the house without my seeing them or knowing that they are there.

Our houses provide habitat for whole communities of animals. Most of the time, everyone lives in relative harmony, until and unless the population of a particular species grows out of control, much like a disease infecting a person. Then things get out of balance for a while, but the community regains its equilibrium in relatively short order, and harmony is restored.

And when you think about it, our bodies have the same kind of function for a variety of organisms. We have a number of bacteria living in our guts and elsewhere. We have fungi occupying various parts of our bodies. We have mites living in places such as our eyebrows. Most of the time, we are not aware of any of these residents, unless the population of a species using us for food or shelter spirals out of control. Then our immune system kicks in and restores the harmony of coexistence in our bodies.

Just like my house, my body provides food and shelter for lots of different organisms. We all live in harmony, sharing the natural world.

Do Ants Think?

Sometimes the days are gorgeous, balmy and calm with the sky a cloudless soft baby-blue. On such days, I am often stuck in a dark windowless auditorium, lecturing to about 100 university students in my animal behavior class. The pull of the day affects us all. I am somewhat less enthusiastic in talking about the computer-generated slides that I am showing, and the class is restless, anxious to get outside to enjoy what is left of the day.

At such times, I switch into discussion mode. I start asking the class questions that can stimulate a conversation and bring out some opinions. The students usually perk up, particularly if the subject is one that really interests them.

One of my favorite topics is the question: do animals think? I start off by asking, how many people believe that humans think? Usually all the hands go up, except for a few contrarians who are not convinced that anyone is capable of thought.

Then I ask, how many people believe that their dog thinks? About half the hands go up. How about cats? Interestingly, perhaps a third of the hands go up. Somehow, dogs seem to have more followers than cats in the thinking category.

Next I ask: how many believe that an ant can think? Almost no hands go up. Virtually everyone seems convinced that ants cannot have any thoughts.

And finally, I ask: how do you know? This generates a lot of discussion that usually revolves around the difficulty of proving that anyone, human or animal, can think. The argument usually follows along these lines: I know that I can think, so by extension, I am willing to concede that perhaps other humans can think. Can I prove it? No, not really. I can provide a battery of problems to solve that seem to require thought, but I cannot conclusively rule out a stimulus-response explanation that would not require thinking. But, because I am human, I am willing to give the benefit of the doubt to my fellow humans.

So why are many people not willing to give the benefit of the doubt to their fellow animals? The students in my class who have dogs usually tell stories of their dogs doing things that seem to require thought. Can they prove that their dogs think? No, not really. But they can identify with the world that dogs live in and the problems that dogs face, and are willing to give them the benefit of the doubt.

But almost no one is willing to give the benefit of the doubt to ants. My students cannot imagine the world of an ant or the problems that ants might face, and are willing to accept that ants do not think. Can they prove it? No, not really.

And here is the key. We are willing to accept that people think, without much proof. We are unwilling to accept that other animals think, also without much proof. Where we can put ourselves into the mind of another animal, we are much more willing to accept that the animal thinks. Otherwise, we assume that there is no thought.

The assumption that animals do not think can be dressed up with all kinds of alleged scientific evidence: The brain is too small, there is no cerebral cortex, the cortex is too small, there are no frontal lobes, and so on.

But the bottom line is, how do we know that an ant does not think? The answer is, we don’t. Unless we are willing to argue from definition. We can define thinking as only a human property, and then we can sit back in great satisfaction that we have solved the problem of animal thinking once and for all.