thepoliblog

Human Brain, Dog Brain, Wolf Brain

Scientiffic reconstruction of a Homo habilis, photographed 25 March 2007 at the Westfälisches Museum für Archäologie, Herne, by Lillyundfreya

People have long wondered about what makes us human.  What underlies our difference from other species of animals?  How did the difference develop?  Why are our brains so large relative to our size, and so versatile?  Why do we have so much cerebral cortex?  Why do we teach and communicate what we have learned, so that – as a group – our collection of knowledge and skills keeps growing and compounding?  Why do we ask sweeping questions about our origin, about the world we live in, and about our future, as an individual and as a group?  Why do we ask whether we have a purpose, as an individual and as a group?

Older attempts at answering these questions in terms of natural processes, focused on factors such as that we walk on two feet, leaving our hands free to become dextrous and make tools.  Other candidates have been language (another type of tool).  It is now widely thought that although such features may have played a role, they miss the most essential parts of the answer.  Other bipeds have nothing like our facility with abstractions.  Some other types of animals have a limited ability to grasp abstractions and to use language and tools.  Some even invent new tools on the spot, to solve a new problem.  But they show no evidence of using a wide range of different levels of abstraction, and as a result their languages are not general purpose.

A promising, widely-considered answer is that the key to our distinctiveness is that for much of our history we lived in small groups, which fared best when their members cooperated with one another and could depend upon one another.  That put a premium on each member of the group being able to figure out what each other member of the group saw and wanted and planned, and therefore whether that individual could be trusted, and how to compete and cooperate with that individual.  It was also advantageous to have that type of information about collections of individuals – cliques.  Our brains had to be able to simulate – to ‘mirror’ – what other individuals were thinking, and would do.  I had to estimate what you were paying attention to at the moment, and also what you thought I was paying attention to at the moment.  I also had to estimate what you knew about what I knew about you, and what I knew about what you knew about what I knew about you.  And so on, in an endless regress.  In other words, there was a great evolutionary advantage for humans who were good at mirroring the minds of other humans, at multiple levels of abstraction.  That also favored the development of the ability to move nimbly from one level of abstraction to another.

Once we had developed the brain mechanisms for that, the same mechanisms conferred other advantages, thereby reinforcing the development of those mechanisms.  They helped us to better anticipate what animals would do, what vegetation would do, and even what inanimate objects would do – the trajectory of an animal, or a stone or a spear.  The same brain mechanisms that helped us to anticipate what human individuals and groups would do, also helped us to better anticipate the behavior of the non-human features of the world around us.  Hence our proclivity to anthropomorphize inanimate objects, including the Sun, Moon and stars, storms, seasons, trees, mountains, seas, animals, and groups of people, both small and large (families, villages, tribes, nations, civilizations).  It is easy to see that these same brain mechanisms would favor the development of superstition and religion.

A remarkable book, Religion Explained, by Pascal Boyer, shows how patterns of thought that develop because of immediate needs are often later applied in ways that are unrelated to the immediate needs that led to them.  He shows how this broadening of the use of a pattern of thought has frequently resulted in a wide variety of superstitions and religious beliefs, as well as in ethnic mistrust.

An example: Each new human needs to develop the sense that some things are dangerous and contaminating.   Those who do are more likely to leave descendents than those who don’t.  So we have evolved to inherit a proclivity to develop patterns of thought that provide that sense.  We do not inherit the pattern of thought itself, and as a result the detailed sense of what is revolting, of what is scary, and of what is contaminating, varies from one culture to another.  But once developed, those patterns of thought are likely to lead to mistrust of those who are not like those in our group.  That can easily morph into ethnic or national hatred, accompanied by feelings as visceral as those that produce revulsion when we encounter a rotting carcass.  Another example of (which was not considered by Boyer) was noticed by Leslie Sanders, a psychotherapist.  He points out that none of us would have reached adulthood without having been watched over, protected, and fed by adults during our infancy and childhood.  That develops in each of us patterns of thought that incline us to later believe that we are being watched, our actions are being monitored, by one or more beings who evaluate what we do, and some of whom might care about our welfare.

A careful anthropolgist, Boyer compares each claim about the human proclivity to religion to the beliefs and practices to a staggeringly wide variety of human groups.  That enables him to show that most of the plausible ideas about religion, both those of believers and those of non-believers, are false.  Boyer open mindedly and comprehensively tests each assertion by comparing it to all of the relevant data.  That makes his work science, rather than advocacy.

Because we evolved to become individually able to learn to mirror the various actors in the world, and to move nimbly from one level of abstraction to another, we developed a sense of ourselves as distinct actors, with a history, a present, and a future.  We came to realize that we had been born, had been little and helpless, had grown, and would die.  This mental development was the reality that legend tries to capture by the story of ancestors who ate the apple from the Tree of Knowledge.

Because we developed the ability to mirror groups of individuals as well as individuals, we also developed abstract (general) concepts, and became capable of abstract thought, and of asking abstract questions.  We went from ‘I want’ to ‘I am’, from ‘my leg’ to the general concept of a leg, from ‘that particular actor that runs on four legs’ to ‘lion’, as a type, and then to ‘I am like those others I live with, and unlike unlike a lion’, and from ‘I will die’ to ‘What is death?’  We developed an urge to understand, that is, to mirror something via patterns of thought that are easy and familiar, so that we are fluent with them.  We also developed an urge to  steer.  Hence legends, literature, philosophy, mathematics, science, engineering, and politics.

By the way, scientists are beginning to identify the regions of the brain that are used for mirroring others.  That is the first step toward understanding how the brain does it.  A pioneer in identifying the relevant regions is Rebecca Saxe, at MIT.  She recently gave a talk for non-experts, which you can see here.  (Look for  the entry for Nov 2 on the web page for Fall 2012.  It should say “Nov. 2, Rebecca Saxe, Massachusetts Institute of Technology, How We Think about Other People’s Thoughts,”.  To see the video, click on the ‘V’ at the right.)

Gyri – anatomical subregions of the cerebral cortex. Author: Patric Hagmann et.al., Published: July 1, 2008, in Hagmann P, Cammoun L, Gigandet X, Meuli R, Honey CJ, et al. (2008) Mapping the Structural Core of Human Cerebral Cortex. PLoS Biol 6(7): e159. doi:10.1371/journal.pbio.0060159

Now about dogs and wolves.  We have seen that mental mirroring underlies much of what makes us human.  But because of their long close association with humans, dogs have evolved mechanisms for sensing human moods – for mirroring us.  Because wolves had no long close association with humans, they rarely mirror us, although, as we shall see, in at least one case they did.

Four tesem dogs (an Egyptian breed believed to be the progenitor of all sighthounds), and a beagle like dog, all in the bottom row, as well as 3 hyenas in the upper row, led on leashes by a man in ancient Egypt.

When I was a baby, my parents lived in a rented part of a house.  The owner and his family lived in the rest of the house.  The owners had a collie dog, Rusty.

A Rough Collie. Photo by sannse at the City of Birmingham Championship Dog Show, 30th August 2003.

If I cried in my crib, Rusty would get under the crib, and then move her back up and down until the rocking motion stopped my crying.

This is very strong evidence that Rusty’s brain could mirror at least some aspects of human brains, since:

– Rusty was capable of realizing that a baby was helpless, and was in some sense to be treated as she would have treated a new puppy.  She knew that crying meant that something was wrong.

– She was capable of feeling discomfort at the unhappiness of someone who was neither herself nor her puppies, someone who played no role in feeding and patting her, but someone who was somehow important to those who did.

– She must have observed human adults rocking the crib – a very peculiar activity that they did not do except with the baby – and was smart enough to draw the connection between this distinctive activity and its calming effect.

– Astoundingly, she must have been able to project ahead, imagining something that she had never seen or done before, namely, herself rocking the crib and calming the baby.

– She must therefore have had some sense of herself as able and willing to have a beneficial effect on others.

– She must have been able to anticipate that the up-down motion of her back could produce an effect that was similar enough to that which the humans produced by the side-to-side motion of their hands.

Striking examples of a dog’s ability to decipher human emotions also appear in the first volume of the autobiography of Dodie Smith, who is best known for having written I Capture the Castle, and 101 Dalmatians.

(A parenthetic note:  I Capture the Castle is a perennially popular novel that is treasured by all who stumble across it, for its convincing portrayal of the turbulent stream of thoughts in a young woman’s mind, and for its perceptiveness about people in general, and for its humor.  101 Dalmatians, long popular as a childrens’ book, is based on an actual Cruella-like offhand remark made by one of Dodie’s friends; the book is much better than the Disneyfied version of it.  Dodie Smith’s four volume autobiography provides a vivid, funny, ground level experience of life in England from 1896 to 1990.  It is the best possible way of refreshing your sense of what it feels like to be a child and then a young adult, and then mature.  It wonderfully captures the episodic way in which our understanding of the world expands.  If you read it, you will never again have a one dimensional, stereotype-based picture of what people were like during the eras she witnessed.)

Now, back to Dodie Smith’s astute dog. The dog was her second, a fox terrier named Peter.  She writes, “He was a highly intelligent dog, particularly clever at hinting at his needs. Long before tea [the English high tea] was ready he could be heard nosing his bowl up and down the hall. … Out for walks with me, he would race ahead to the sweet shop and put his paws on the window, as if choosing his pennyworth. But his most brilliant achievement was a seemingly psychic pre-knowledge of the days he was at risk of a bath. He was supposed to have one every month or so, given to him by our weekly washer woman, but one day she got soap in his eyes, and after that he left every Monday morning long before she arrived and when there was no indication that she was coming. He stayed away until she had gone, frequently returning covered with mud. At last my mother, who had bathed him when he was a puppy, took the job on again. He liked this so much that he would stand up at wash-basins and invite baths.”

Two smooth fox terriers, photographed 23 March 2008 by Franek B (www.bisiki.pl).

Many anecdotes show that dogs feel emotional attachment to the individual members of their human ‘family’: joy, when a loved member of their human ‘family’ reappears,  and grief when a loved member of their human ‘family’ dies.  Elephants clearly show emotional attachment to one another, and show grief when a member of their group dies.  Grief over another individual has several ingredients: the individual is missed, the griever realizes that the missed one’s absence is permanent, and the griever is reminded of their own mortality and also grieves for that.  The first ingredient surely occurs for both dogs and elephants.  Although the first ingredient does not involve mirroring or projection into the future, the second ingredient does.  (The third ingredient probably requires too long a projection into the future to apply to a dog.)  Anyone who has observed a grieving dog or elephant senses that the animal’s grief includes the understanding that the missed one will never return.  Admittedly, in the absence of brain-imaging, that inference is based on our own human mirroring of the animal.  Although there can be pitfalls in basing a conclusion on mirroring an animal that is not completely like ourselves, in this case the mirroring produces a strong signal.  Also, our mirroring of our pets usually predicts their reactions quite accurately.  So we can be fairly confident that a dog’s grief includes the understanding that the missed one will never return.

Now consider wolves.  The evolution of wolves did not include selection pressures produced by long term close association with humans.  Unlike dogs, wolves have not evolved a special proclivity to learn to mirror humans.

Wolf in Denali National Park, 2 June 2010, photo by Ken Miller.

But wolves live in packs, and they have developed the ability to mirror each other.  Once developed, that capability presumably also enables them to partially mirror their prey and their predators.

A striking example was experienced by Farley Mowat, and is chronicled in his book, Never Cry Wolf.  He was in the Canadian arctic, studying the behavior of a single pack of wolves.  The pack had gradually become accustomed to his presence, and neither feared him nor regarded him as prey.  Each evening, individual wolves would leave the pack’s home location and go out along well worn paths to look for small prey, returning in the early morning.  Farley Mowat’s  tent happened to be near one of those paths, and he eventually became annoyed at being disturbed early every morning by the close passage of a returning wolf.  He had noted how the wolves marked their individual territories within the pack, so one evening he drank an especially large quantity of tea, and then he marked all along a rectangle that was centered on his tent.  Since the rectangle crossed one of the well worn paths in two places, he awoke early the next morning to see what would happen when a wolf encountered his boundary.  After a while, a wolf wearily trudged homeward along the trail, not looking about, because the trail was so familiar.  When the wolf reached the scent-marked boundary, it stopped, startled.  It looked over at Farley Mowat’s tent, and then went along the marked boundary until it reached its other intersection with the trail, and then resumed its normal trail.  The wolf had mirrored Farley Mowat.  It had treated him as a member of the pack.

Male forest elephant at the Langoué Bai (forest clearing), Ivindo National Park, Gabon. This male came to the clearing to drink mineral-rich water, obtained from pits dug by elephants at specific locations within the clearing. Photographed 8 November 2007 by Peter H. Wrege.