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Pointed Observations

Posted on March 26, 2011
by Dinesh Dutt

Maya is intensely curious about people and their interactions. When we go to a restaurant, she can’t stop swiveling around to try and see everybody who’s in the place. People next table are subject to intense scrutiny if they’re engaged in an animated conversation. “She’s your daughter”, Shanthala usually says when this happens. At times, Maya points at the people and asks us what they’re doing or tells us her thoughts on what’s going on or attempts to mimic their conversation. All this of course results in our gently hushing her and trying to get her to not stare at people so much or even point. Pointing is rude, we say, people don’t like being pointed at. She’s even more curious about the denizens closer to her age. If a child is crying, she stops everything she’s doing and stares at the child and the adult(s) involved at the scene. Sometimes, she gets right up in their face as the adults attempt to pacify or admonish the child. She then comes to us and pointing at the child informs us that the child was crying and asks us why. More hushing and more “please don’t point” statements.

At such times, I often wonder, at the origins of the rituals we ask Maya to engage in or desist from. Is the behavior universal or predominantly Western or Indian ? Is it quite old or was it relatively unknown as recently as when I was a child ? What about other animals, do they have similar behaviors ?

Yesterday, I came across an article in one of the blogs that I often follow, ICICI. The article was titled “Human avoidance in pointing: a cultural universal?” The author of the article wondered about the universality of pointing and the reasons for its taboo. He requested fellow anthropologists and other similar practitioners to respond. Reading the responses and the links to the papers that were put out and engaging in a little contemplation on my own provided interesting insights into yet another fascinating aspect of human and animal behavior.

Consider the following experiment. There are two opaque bags and into one, a person places some food. A chimpanzee is shown the two bags and two different things are tried. In one case, the bag with the food is pointed at by a person. In another case, the bag with the food is tilted so that the chimp can see the food. What do you think the chimp does in each case ? In a different experiment, instead of pointing or tilting, one of the experimenters deliberately marked the bag with food with a large X and clumsily dropped the marker into the other bag. Which bag do you think the chimp chose ? Now instead of a chimp, if a toddler is brought in and the experiment is repeated. What do you think the toddler does in each case ?

The chimps picked the right bag when the bag was either tilted or marked (they seemed to note that the dropping of the marker was accidental and ignored that and went for the bag with the X), but they failed to pick the right bag when it was only pointed at. Just to be clear, if one chimp stares at an external location, another chimp can follow the gaze and venture up to the spot targeted by the gaze, even looking back at the other chimp if there is nothing there. In other words, they can “project an imaginary line of sight through invisible space”. But they do not point or follow pointing. It appears that pointing is a human trait. This is fascinating.

As a parent, I engaged in pointing very early on with Maya. Naming various objects involved pointing. Current research seems to indicate that around their first birthday, infants begin to point to draw an adult’s attention at something that caught their eye. Researchers differentiate between two different ways infants use pointing. Infants point to get something, say “get me that ball daddy”, and they point to direct the adult’s attention at something of interest, say “look at that bird daddy” (I’m not saying they can verbalize bird or ball, of course). Interestingly, autistic kids only engage in the first kind of pointing (called protoimperative i.e. a rudimentary command) and not in the second (called protodeclarative i.e. a rudimentary declaration). Even apes raised by humans can apparently engage in protoimperative pointing but not in protodeclarative pointing. Postdeclarative pointing to achieve joint attention is considered by many to be a key step in infants developing a theory of mind (i.e. the knowledge that people have mental states which can lead to certain behaviors and that other’s may have mental states different from one’s own). As the author of the ICICI blog entry notes, pointing is a trait acquired in humans even before the onset of human language.

If pointing is such a key characteristic, why do we then dissuade its use as we grow older, i.e. why is pointing such a taboo ? There are several reasons given, all slight variations of each other, in my opinion. Pointing is calling attention to or singling a person out for some specific reason and the reason is usually not complimentary. Pointing seems entwined with blaming or accusing in our society. As the Dire Straits song goes, “When you point your finger ‘cuz your plan fell through, You got three more fingers pointing back at you”. And there is of course the well-known term “finger-pointing”. Further, the person pointed at, feels isolated and loses the safety of being invisible in a larger whole. Another possible reason is that pointing implies a dominant-to-subordinate relationship such as in a parent-child case. We point at our children and admonish them to not engage in some behavior. One commenter on the ICICI blog narrates an anecdote from Ecuador where a mother explained that it is dangerous for a child to point because of the evil eye of the person being pointed to. In short, pointing is very threatening.

So is it a universal taboo to not point ? One of the commentators to the ICICI blog article says that based on his work with the Yucatec Maya in Mexico, he doesn’t think they  consider pointing taboo. But that’s about the only evidence I found that the taboo against pointing is not universal.

Pointing gets convoluted to get around the taboo of not pointing. People in Southeast Asia such as Laos and indigenous people in Southern America, Africa and Australia engage in “lower lip pointing“. The Vezo in Madagascar use a fully bent index finger to point at superiors and those they revere including whales. And of course, there is the Judas kiss.

Another fascinating piece of information that I learned is that there is a disorder called heterotopagnosia in which the patient is unable to point at someone else’s body parts. They pointed at their own body part when asked to point at another person’s body part. They had no problem grasping the other person’s body part, they just couldn’t point to it. The Neurocritic blog has more information about this strange malady.

Little did I know when I first started down this path, of the simple act of pointing.

I’m working on my poems and working with
my fingers not my head. Because my fingers

are the farthest stretching things from me.
Look at the tree. Like its longest branch

I touch the evening’s quiet breathing. Sounds

of rain. The crackling heat from other trees.

The tree points everywhere. The branches can’t
reach to their roots though. Growing longer they

grow weaker also. Can’t make use of water.
Rain falls. But I’m working with these farthest stretching

things from me. Along my fingertips bare shoots
of days then years unfurl in the cold air.     – Long Finger Poem by Jin Eun-Young

References:
1. Twelve-month-olds point to share attention and interest, Liszkowski et al, 2004.
2. Understanding and sharing intentions: The origins of cultural cognition, Tomasello et al, 2005.

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The Birth of Language

Posted on August 2, 2010
by Dinesh Dutt

It seems like I waded into the middle of a blog brawl between Razib Khan and his dislike of linguistic anthropologists and linguistic anthropologists. Razib not only commented on this blog but also put a pointer to my entry on the death of the Bo language .

In his entry linking to my article, Razib writes:

“… this experience only reinforces my disrespect for the ‘discourse’ which linguistic anthropologists are introducing into the public domain. There are intellectual reasons to be interested in linguistic isolates not part of the big language families (e.g., Semitic, Indo-European, Niger-Kordofanian, etc.), but no language is “70,000 years old.” The Andaman Islanders are not black-skinned elves, immortals who brought their culture in toto from the ur-heimat of Africa, genetic and cultural fossils who have been in total stasis. Cultural anthropologists presumably understand that all humans are equally ancient, derived from African ancestors, and that all languages and peoples are African (or at least 95% so within the last 100,000 years), but their communication to the public confuses the issue and presents some groups as ‘pristine.’”

I had quoted what the BBC article had reported without being overly skeptical about the details. Based on his comments, I decided to educate myself a little more. A lot of things stuck out as possible outcomes from the quote, different from the one that Razib was quoting. A primary possibility was that the BBC reporter was the culprit, misquoting (I’m not saying deliberately) the linguist in question, Dr. Anvita Abbi. Another puzzling fact was that many, but not all, news outlets quoted that the Bo language was thought to be 70,000 years old. Did they all get it wrong or were they merely picking off a common source ? But, first I wanted to find out the current consensus on when language evolved.

Language is not just a means of communication, but “a distinct piece of the biological makeup of our brains”, not unlike bipedalism, as the famous linguist, Steven Pinker, put it. Language is also not the same as speech, as evidenced by the presence of sign language. And for those of us who think sign language is a fairly modern invention, a signing form of English, Steven Pinker writes in his bestseller, The Language Instinct: “They [sign languages] are found wherever there is a community of deaf people, and each one is a distinct, full language, using the same kinds of grammatical machinery found worldwide in spoken languages. For example, American Sign Language, used by the deaf community in the United States, does not resemble English, or British Sign Language, but relies on agreement and gender systems in a way that is reminiscent of Navajo and Bantu.” Finally, it is important to remember that there are languages which do not have a written form.

These three points are important to understand how we can approach the question of the origin of language. First, humans had to evolve the appropriate neural circuitry for language and they had to evolve the appropriate physical circuitry for speech. But, these two could evolve separately and distinctly. Finally, non-written languages could have been existence before the first written language or written languages could have existed prior to their being set to writing. The Wikipedia quotes the interesting case of Sanskrit, where the earliest parts of Rigveda are thought to have originated around 1500 BC while the first available written version is in the 11th century A.D.

When I asked Shanthala how old did she think language was, smart as she is, she quickly honed in on the question of how could we determine the ages of purely oral languages. If oral languages leave no fossils behind and written languages came much after oral, how can we determine when language evolved ?

We can attempt to answer the question of origin only obliquely, and with an uncertainty that only gets larger as we probe at the edges of the homo lineage. Based on fossil evidence, the oldest modern homo sapiens are dated at about 200,000 years and thought to have migrated out of Africa about 100,000 years ago. The consensus, as far as I can tell from reading the data that I could find, seems to be that human language came into existence somewhere around this period. The idea as stated by Pinker is that all branches of humanity that spread out of Africa evolved language and therefore it must have been around already when the migrations began. Debate about whether a proto language existed before then is the subject of continuing debate. The Wikipedia and especially books such as Pinker’s and Christine Kennealy’s “The First Word” are superb references for those wishing to dig deeper.

Still, is it absurd to say that a language is 70,000 years old ? Languages naturally evolve and it should at least strike one’s skeptical bone that a language could be that old. Even on the extremely remote off chance that this one didn’t, what evidence did they have to speculate its age ? I contacted Dr. Abbi to check if she had indeed said that the Bo language was that old or was the reporter misquoting her. She responded promptly:

“Yes the press has made a mistake. No language in its present form can be claimed to be that old. Linguists can reconstruct with some surety upto 10,000 years and in cases of isolated languages much longer, but certainly not beyond 15000.“

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Culture and Parenting In Kidspeak

Posted on September 30, 2009
by Dinesh Dutt

The intersection of culture with parenting has been on my mind ever since Maya was born. I’ve written about it a few times already. Today, I read an article on NYT titled Parents Need to Tune In and Engage a Young Child With Talk that once again reminded me of it. The article exhorts parents to engage verbally with their children, because it is good for the children’s language development. If we don’t talk to our kids, they’ll miss out on social and verbal cues and this negatively impacts development. Some quotes from the article:

“‘Talk to your baby whenever you have the chance,’ the American Medical Association advises parents.”
…
“Help expand your child’s vocabulary by talking about what is done with various objects or why a particular food helps to build healthy bodies.”
…
“Count the steps as you go up or down. My twin grandsons’ math skills flourished long before they could speak in sentences because they live in a third-floor walk-up.”
…
“And you can’t introduce books too early. I remember my niece at 3 months paying rapt attention as her mother “read” picture books to her, pointing out objects, their colors and what the characters were doing.”

I was left thinking that if I didn’t talk or read to Maya all the time, she’d be somehow deficient in her verbal and social skills as she grew up. I think that if I hadn’t read as much as I have, I’d feel the pressure to talk to her all the time. And if I didn’t, I’d feel less of a parent, that I’d somehow failed her.

To get a different perspective, let’s turn to Meredith Small’s “Kids: How Biology and Culture Shape The Way We Raise Our Children”, her excellent follow-up to the brilliant, insightful, “Our Babies, Ourselves”, which I’ve written about before.

Small says that anthropologists and other scientists who have studied children and language acquisition across cultures have found that children employ a variety of strategies to start speaking, and that all these strategies work fine. Some examples of these differences:

  • The Gusii of Northern Kenya think that spending as much time as the Westerners do, talking to the children, molds the children to be selfish and self-centered adults. Recognizing from experience that children speak fine without talking to them incessantly, they don’t spend much time talking to them, but carry their children everywhere and thus immerse them in a sea of adult interactions all the time.
  • Similarly, the Kaluli people of New Guinea live in a non-literate society and instead of talking to the child, face the baby towards others and speak for the non-verbal baby in a three-way conversation. Again, the baby is carried everywhere and is awash in conversations all the time.

In the 1950s, when behaviorism ruled the roost, linguists believed that speaking was a learned ability, that children learned to speak by listening to others. Then along came Noam Chomsky who revolutionized linguistics with a convincing argument that language is innate, biological and that we’re hard-wired from birth to speak. Steven Pinker, a leading linguist and science writer says that children instinctively know things about language that no one could have taught them. For example, Patricia Kuhl, a major figure in the study of language acquisition has conducted research that demonstrate that infants as young as 18 weeks are sophisticated in the visual aspects of speech. An infant is shown say two pictures with identical faces, but one making a silent “aah” vowel sound and another making a silent “eee” vowel sound. The infant is then made to hear one of the two vowel sounds i.e. “aah” or “eee”. Infants are shown to stare longer at the picture that corresponds to the vowel sound they’re hearing. Another example that kids know about language without being taught is the ease with which they construct plurals of new words.

While there are several theories about why we as a species acquired language, the predominant one is that language is a tool for socialization, one that takes the place of grooming that other apes use. This theory is borne out by observations that the key for an infant to acquire language is to be exposed to it. And not any exposure will do, it has to be live adults communicating. It cannot be a TV or DVD edutainment program that purports to teach the infants new words or new languages. Andrew Meltzoff, another prominent researcher in the field of infant development is quoted in Parenting Inc.: “From what I’ve seen of the science, there isn’t a tape in the world that can teach a nine-month old baby how to read. It goes against everything we know about the evolution of language in human behavior”.

It is well known that children from rich verbal enviroments tend to possess a larger vocabulary. But this comes at a much later stage in development. Statements such as: “And you can’t introduce books too early. I remember my niece at 3 months paying rapt attention as her mother “read” picture books to her, pointing out objects, their colors and what the characters were doing.” from the NYT article are without basis, according to current research.

But environment does play a critical role in language development. A tragic example of failed language development due to a severely malnourished environment comes from the sad story of a child named Genie. She was locked in a room alone, chained to a potty chair, from the age of 18 months by her mentally retarded father. She was never spoken to or allowed to speak. She eventually escaped from this prison with the help of her (also mentally challenged) mother, when she was thirteen years old. Despite being exposed to language at this stage, her verbal skills never progressed beyond that of a child. Five word sentences is the most that she can make. Stories such as Genie’s sear my mind.

Language is a prism that affects how we view the world and how we construct the world, said Edward Sapir, an anthropologist cum linguist. This is called the Sapir-Whorf hypothesis and after spending some time in the dustbin, is undergoing a revival thanks to the new work conducted by linguists such as Sara Boroditsky. Small agrees with this hypothesis and says that a society’s idea of identity informs the form of verbal coaching that occurs. In Western societies where an individual is considered paramount, nuclear families give rise to the dyadic conversations discussed in the NYT article. Among the Kaluli, an egalitarian society, life is considered to be a multifaceted interaction and so mothers involve children indirectly in conversations with others rather than talking one-on-one with them.

As a reflection of societal norms, language is one important way children learn about gender and status norms sanctioned by the culture. Small says that studies have shown that in the West, fathers speak differently to the children compared to the mothers. About thirty percent of a father’s speech consists of imperatives such as “Do this” or “Don’t do that” and speak that way more with boys than girls. Western mothers tend to talk in longer sentences to the children and talk the same way with both boys and girls. Children mimiced the adults with boys tending to use imperatives and commands. One study found that two year olds were aware of this gender-specific use of language.

When we went to the pediatrician for Maya’s 15th month checkup, she didn’t seem too pleased that Maya didn’t speak any legible words. Despite our nonchalance at this news, Shanthala and I were a little concerned if Maya had any problems. Articles such as the one in NYT exacerbate the concern by throwing guilt into the mix. I remember asking several parents at what age their kids spoke and resting easy when one of them said that their son spoke only when he was two.

In such a culture, books such as Judith Rich Harris’ “Nurture Shock” which I’ve written about earlier, make sense. A lot of culture gets passed on as gospel by the medical association. It is not that parents don’t matter, it is that the issues over which the parenting style is considered paramount are not so.

The NYT article quotes a speech and language specialist, Randi Jacoby: “Reward your little one’s communicative attempts with your heightened attention to his/her conversation. Be prepared to put down your cellphone and look them squarely in the eye as they share their thoughts with you.”

Now, that is something I can agree with. Not because it benefits the verbal development of the child, but because we teach them that when conversing, paying full attention and listening is important, that talking to a person, a child, is more important than talking on a cell phone. Given how facile it is to be focused on the cell phone or the laptop, being mindful of interacting fully with the child may set a tone for how they listen and talk, not how soon they talk.

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Birdbrain

Posted on August 9, 2009
by Dinesh Dutt

Countless stories I heard growing up, involved animals as the main characters. In Indian mythology such as Ramayana and Mahabharata, animals played a key role, be it as the trustworthy and loyal Hanuman, the brave Jatayu who dies trying to protect Sita from Ravana or Garuda, the ride of gods. They were even the god themselves, as in Ganesha, the god with an elephant’s head. And who can forget the stories from the Jataka tales, Hitopadesha and Panchatantra with their wondrous, imaginative and moral stories in many of which animals were the only characters. When my eyes turned to the west, I ran into the cute, cuddly Mickey Mouse, Bugs Bunny, the ever grumpy Donald Duck, Elmer Fudd and the dumb, but with a heart of gold, Goofy.

The animals led lives not unlike humans in many of these tales, possessed of speech, likes and dislikes and full of intelligence and spirit. Monkeys played pranks, laughed heartily, shed tears of remorse, mice fell in love, snakes conspired and birds sang and gossiped. I knew fairly early that dogs can’t talk no matter how much Goofy does and when I saw the monkeys, realized that their lives were different from humans.

Though revered and a part of the child’s landscape across cultures, just about every culture considered them to be less than humans. In Hinduism, if you commit enough grave sins, you are reborn as an animal such as a dog or a pig. If you do good as a dog, such as give your life for your masters, you can be reborn as a human. In the west, where Christianty played (and continues to play) the central role in attitudes to animals, man ruled over the world and animals, considering it fit to use the animals as he saw fit, making it perfectly acceptable to treat them as badly as one wanted to, either by killing cats in the hundreds of thousands or rendering hundreds of thousands of animal species extinct in our path to modernity.

And animals could never be intelligent, for any definition of intelligence you could conjuncture. And could not love or mourn. If they shed tears, they were only the fake tears of a crocodile. As time elapsed and people began to study the animal life more closely, the broad generalizations of their inferiority began to fall apart. So, we constructed narrower and narrower definitions of intelligence, love and mourning to keep our superiority intact. And we showed our contempt for their minds with terms such as birdbrain. Three pieces of recent research call into question whether that is even derogatory.

Using Tools

Tools, making them and using them, were long considered the dominion of humans alone. Then people like Jane Goodall brought us observations of chimps using long leaves to tease out ants through the tiny openings in ant hills. So we grudgingly allowed some tool making capabilities to the greater apes, the primates, the ones closest to us. And though we remembered the stories of crows using stones to raise the level of water in a pitcher to a reachable level, we didn’t think they were true.

A story I came across on Yahoo news yesterday concerned new research that showed rooks, a cousin of crows, that used stones to raise the water level in a narrow pitcher to reach a worm floating in the water. The study states that the rooks seemed to understand instinctly that dropping stones would rise the level of water. Further, they also seemed to know how many to drop and learnt quickly that the bigger stones got the worm early. When presented with a bowl containing sawdust instead of water, the rooks learned that using the stones didn’t help.

The accompanying commentary to the article professes some skepticism that the rooks really understood the properties of water or that they were dropping stones instinctly rather than as a behavior learned during another experiment. I found the skepticism rather strange in trying to equate crow cognition with human cognition. I think this shows a fundamental misunderstanding of cognition and evolution. We, just like other animals, evolved in ways that were adaptive and advantageous to the environments we lived in. In other words, our intelligence is defined and limited by our bodies (mind is embodied) and the ecology in which we evolved. Birds such as crows occupy different ecological niches compared to us and so have evolved different strategies than us. Its as if the crows conducted experiments on humans ability to fly and decided that we couldn’t do it as instinctively or as well or in a similar manner as they.

The Yahoo article also posts a link to a Youtube video showing the rooks using stones to reach the worm.

This is not the only experiment that shows birds can use tools. Many other tests done in the recent past show that birds, especially of the crow family, are quite adept at using tools to get what they want.

Recognizing Faces

I came across this article last year and noted it, but failed to blog it earlier. The article speaks of research conducted in the urban landscape of Seattle. The researcher, John Marzluff, a wildlife biologist at the University of Washington, used two face masks. His team of researchers always captured a bird and banded it using one of the guises before releasing them. In the months that followed, the researchers walked the neighborhood, sometimes wearing the mask in which they captured the birds and sometimes using one that was not used in capturing the birds. They found that the birds constantly harangued and scolded them when they wore the masks that was used to capture them. And more significantly, this information seemed to have been communicated to other crows in the neighborhood because they were scolded by 47 of the 53 crows in the neighborhood, far more than the number they trapped.

Dr. Marzluff extended his study now to many parts of Seattle, used a half-dozen new more realistic masks made by a professional mask maker and added volunteers who didn’t know the history of the masks. Wearing some of the “dangerous” masks, Dr. Marzluff and his research team trapped and banded several crows in and around Seattle. Then, they asked volunteers to walk around the neighborhoods where the crows had been trapped. Unaware of the history behind the mask, some volunteers wore the “dangerous” mask and others wore a mask that had not been used to trap crows. As one of the volunteers reported:

The reaction to one of the dangerous masks was “quite spectacular,” said one volunteer, Bill Pochmerski, a retired telephone company manager who lives near Snohomish, Wash. “The birds were really raucous, screaming persistently,” he said, “and it was clear they weren’t upset about something in general. They were upset with me.”

The crows deliberately targeted only the volunteers wearing the dangerous mask even in the presence of other volunteers wearing the neutral masks. According to Dr. Bernd Heinrich, a well recognized authority in the study of ravens, this ability to recognize faces is an offshoot of the ability of crows to recognize each other even after several months of separation.

Why the mask, the more perceptive reader may ask. The researchers say they used the mask to test the recognition of faces specifically as compared to the clothing, the gait and other human traits.

Self Recognition

One of the last holdouts of our superiority over animals is self-recognition. When we look in the mirror, we know we’re looking at a reflection of ourselves. We can use this information to indulge in all sorts of narcissitic things such as grooming ourselves. Even human babies are considered to not pass muster until they’re at least a year or so old. We then grudgingly admitted that four primates, the elephant and the bottlenosed dolphin had the ability to self-recognize themselves in the mirror. But a bird, a non-mammalian life, one that doesn’t even possess the same brain machinery as the mammals, machinery such as the neocortex, thought to be the seat of self-recognition ? Not a chance.

Last year, a study found that Magpies, another cousin of the crows, can recognize themselves in the mirror. The researchers in Frankfurt, West Germany, placed a red, yellow or black mark on a group of five magpies. The black mark couldn’t be differentiated from the bird’s own black feathers. The mark was only visible in a mirror. When presented with a mirror, the birds looked at themselves and the ones with a red or yellow mark, attempted to peck themselves in the spot where the mark was.

Says lead researcher Helmut Prior: “It shows that the line leading to humans is not as special as many thought…. After finding this kind of intelligence in apes, many people thought it had developed once in one evolutionary line with humans at the end. The bird studies show it has developed at least twice”[Reuters].

The popular science magazine, Discover, listed the discovery as one of the top 100 discoveries in science for the year 2008.

It was through Kitty that I grew closer to feeling a kinship with other animals. Life with him was a continuous process of growing closer. When he first came to be with us, he wouldn’t let us touch his belly. As time passed, he allowed us to touch his belly, his front paws and finally, he sat on our laps and kneaded our chest with his paws, the ultimate act of being allowed into the feline world. The ways in which he acted with me, I wondered if he loved me. I remembered a line from Ayn Rand: “Love is making exceptions”. In that sense, I can say Kitty loved me. He made exceptions with me.

One day, we might find that it is we who’re being studied by the animals all this time, as Douglas Adams wrote tongue-in-cheek in the hilarious “trilogy in four parts”, “Hitchhikers Guide to the Galaxy”. The dolphins eventually leave Earth, having concluded their experiment on humans and in parting they say “So long, and thanks for all the fish”.

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To Walk, To Perchance Be Human

Posted on May 12, 2009
by Dinesh Dutt

It was a beautiful spring evening, this past Thursday. Maya was just shy of her 15th month birthday that evening, when she walked a little over a half mile.

Shanthala was on call and so Maya and I set out for an evening stroll. A neighbor walking their dog, still a puppy and not easily controlled, pushed us off our usual path. I walk Maya on the sidewalk, almost never crossing the street. I expected Maya to continue the routine. But, as we reached a traffic light on this new path, Maya stopped and gesticulated at the pedestrian crossing button, insisting that I press it. I was flabbergasted, I hadn’t realized how much she was imbuing when she was with us. I acted dumb and asked her what she wanted, to confirm that this was not a fluke. She pointed to the button and gesticulated again, this time more impatiently. After I pressed it, she gesticulated her desire to be picked up. Next, she pointed in the direction she wanted me to cross the street. I was even more surprised. This was the route when I took her running, but I didn’t think she would recognize and register this much information.

She demanded to be put down once we crossed the main street. From there, she walked all the way upto a neighborhood park. Walking with her is never a surgical operation. She stops many times along the way, examining the neighborhood, the passing cars, the passersby. She is happy to greet people who smile at her. A resident of one of the houses emerged with her 4 or 5 year old son and Maya rushed up to her, smiling and indicating that she wanted to hug the boy. All along the way, people stopped to admire this little girl, walking with such happiness.

Since Maya started walking when she was about thirteen months old, every day I take her for a walk around the block of our neighborhood. We’ve taught her to not pluck flowers, but to just touch them or smell them. So she just touches a flower or two in each bush and says “Ta”. When we get to a rosemary bush, she rubs the leaves and then rubs her face, her nose crinkling with pleasure. That spot is one of her two favorite stopping places on our walks.

Sometimes, Maya wakes up in the middle of the night and if I’m not around, starts whimpering before bellowing a full throated cry and starting her search for me. She realized that one of the spots I can be at is the toilet and so she checks there first. Before she could walk, she would crawl. Alerted by her quest by the baby monitor, I’d usually reach her before she had gone very far. Nowadays, she’s already waiting by the gate at the top of the stairs before I reach her. Since she has started walking, she rarely crawls. It is as if a switch has been turned on.

Why do we take so long to walk ? Walking involves maturation of both the muscles required and the sections of the brain responsible for controlling and coordinating the motion. The motor skills develop from head to toe i.e. we learn to control our face and neck much before we learn to control our hands and legs. Which is why babies can smile, stick their tongue out and hold their head up before they can sit, stand and walk. The motor nervous system is an incredibly complex piece of neural circuitry relying on a feedback loop to control the movements till they eventually become smooth. Many parts of the brain including the cerebrum, cerebellum and basal ganglia have to all mature before something as complicated as walking can occur. The whole process is quite hardwired i.e. little can be done by parents to accelerate it. Motor milestones (when the infants achieve a motor skill such as walking) are about the same across cultures as different as the Hopi Indians where infants are kept strapped to their mother’s back with little movement possible to modern middle class urban cultures where people attempt to give infants tummy time, kicking exercises and walkers.

Why did we start walking ? When did we start walking ?

The earliest known bipedal animal was a reptile whose fossil dates back to 290 million years. While dinosaurs and many birds (such as Ostrich) evolved to be bipedal, among primates, none are like humans in being exclusively bipedal; they’re bipedal for only some of the time. We had to undergo several structural changes to be bipedal, changes that prevent us from becoming efficient quadrupeds. For example, our hip joint is larger, shorter and broader than that of our primate cousins. Our toes are smaller, meant for motion rather than grasping as is the case with our nearest primates. One of the traits for classifying a fossil as an ancestral human (called hominins) is evidence of bipedalism. Until the discovery of the fossils of a creature named Orrorin tugenensis in Kenya in 2000, bipedalism was thought to have evolved around two to three million years ago. But this discovery dates this development around six million years old (the discovery also pushed back the split between chimps and hominins to seven million years).

We still do not know with certainty why we stood up and stayed up. Wikipedia mentions the existence of as many as twelve hypothesis that attempt to explain the origins of bipedalism. This article on Nova, the popular science show from PBS lists the various hypotheses. The one that I knew from a long time ago is called the Savannah hypothesis. As thick evergreen forests gradually disappeared and made way for wide swaths of grassland (savannah), staying on all fours with organs developed to hang from trees became less advantageous than walking. Standing up also allowed us to see farther. Another popular hypothesis is that walking endowed us with reproductive advantages. With our hands freed, we were able to carry back more food, thereby making the bipedal men more attractive to women. Another theory suggests that being bipedal allowed us to more efficiently conserve and dissipate heat. A biped apparently has a 60 percent reduction in the heat load compared to a similarly sized quadruped which in turn meant less water requirement. While many of these theories have fallen out of favor, the story remains without an end. Our bipedal origins remain a mystery.

A humorous aside. A colleague at work has this cartoon by his desk. I found this image courtesy of infiniteuser.


This evolutionary adaptation is not without its side-effects. My grandmother and my mother both suffer from severe arthritis, especially of the knee. I don’t remember my grandmother ever walking without limping, a sort of shitfing of weight to the outer side of the knee rather than directly on it, as she put one foot in front of the other. On days when her knee is tender, my mother walks like that now. Every once in a while, I take a gluosamine tablet because I’m afraid that with all my running and my mother’s genes, I’ll develop arthritis. Interestingly, arthritis has been discovered in the fossils of ancient hunter-gatherers. On Shanthala’s side, her mother suffers from severe lower back problem, something that flares up occasionally in Shanthala too.

Bipedalism also put us in conflict with our other singular characteristic, our rather large brains. Long, narrow pelvis gave way to short, wide hips to provide for a stable bipedal locomotion. This also narrowed the birth canal through which the baby had to squeeze through, putting both the mother and the baby at greater risk during delivery. We went from being gorillas with a 20 minute easy, almost painless labor to twelve hour labors, epidurals and C-sections. The small, flexible brains required for our narrow passage to the world, also meant that the brains in human infants needs a lot more maturation. Our brains continue to grow at a rapid pace, even after birth, hardly slowing down till we’re a year old.

So what came first ? The walking or the talking ? Lucy, possibly the most famous of all hominin fossils, along with much other evidence seems to indicate that bipedalism evolved before our larger brains. This is now generally accepted and some theories even argue that bipedalism may have spurred the evolution of larger brains.

Almost anything in our development can go wrong. Is there something that can make us become quadrupeds again ? In 2006, a Turkish professor, Uner Tan, reported the discovery of a family of 19 in which five individuals walked on all fours. Uner Tan dubbed the disorder, Unertan Syndrome. However, there is controversy over whether the behavior is caused by genetic defects or by the way in which they were raised. As Prof. Sean Carroll says on Nova: “The central question is not really whether a single mutation could lead some individuals to walking on all fours, but rather whether a single mutation could lead normal apes walking on all fours to walking upright. And this is completely invalid. From what we understand from both genetics and the fossil record, the process of becoming upright involved all sorts of changes in our ancestors, in our skeleton and in our musculature, in various parts of the body. And from what we understand about genetics of building those body parts and reshaping those body parts, it had to involve many genes and changes in those genes assimilated over a long period of time.”

In March 2008, an article was published in the Proceedings of the National Academy of Sciences in which the authors claimed: “Our data indicate that mutations in VLDLR impair cerebrocerebellar function, conferring in these families a dramatic influence on gait, and that hereditary disorders associated with quadrupedal gait in humans are genetically heterogeneous.” But the conclusions of this study have been refuted and there is general agreement that a single gene cannot be responsible for bipedalism.

Having reached the end of her rather long walk that Thursday evening, Maya sat down on the sidewalk by the Stop sign that marked 0.53 miles. I picked her up and carried her back to the house. But she was not done yet. She didn’t want to get back in and so we continued our walk around the block. Around the corner from our street, sprinklers came alive, spraying water onto the manicured lawns, spilling some onto the sidewalk. Maya ran towards the spray, stretching her hand out to feel the water. She looked at me and not seeing any sign of disapproval, waded into the middle of the lawn, screaming in delight at the water spraying her from all directions. I took her home a few minutes later. She was soaked, and deliriously happy.

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