## Correlation and causation

So I have this lecture on “smelling (statistical) bullshit” that I’ve delivered in several places, which I inevitably start with a lesson on how correlation doesn’t imply causation. I give a large number of examples of people mistaking correlation for causation, the class makes fun of everything that doesn’t apply to them, then everyone sees this wonderful XKCD cartoon and then we move on.

One of my favourite examples of correlation-causation (which I don’t normally include in my slides) has to do with religion. Praying before an exam in which one did well doesn’t necessarily imply that the prayer resulted in the good performance in the exam, I explain. So far, there has been no outward outrage at my lectures, but this does visibly make people uncomfortable.

Going off on a tangent, the time in life when I discovered to myself that I’m not religious was when I pondered over the correlation-causation issue some six or seven years back. Until then I’d had this irrational need to draw a relationship between seemingly unrelated things that had happened together once or twice, and that had given me a lot of mental stress. Looking at things from a correlation-causation perspective, however, helped clear up my mind on those things, and also made me believe that most religious activity is pointless. This was a time in life when I got immense mental peace.

Yet, for most of the world, it is not freedom from religion but religion itself that gives them mental peace. People do absurd activities only because they think these activities lead to other good things happening, thanks to a small number of occasions when these things have coincided, either in their own lives or in the lives of their ancestors or gurus.

In one of my lectures a few years back I had remarked that one reason why humans still mistake correlation for causation is religion – for if correlation did not imply causation then most of religious rituals would be rendered meaningless and that would render people’s lives meaningless. Based on what I observed today, however, I think I’ve got this causality wrong.

It’s not because of religion that people mistake correlation for causation. Instead, we’ve evolved to recognise patterns whenever we observe them, and a side effect of that is that we immediately assume causation whenever we see things happening together. Religion is just a special case of application of this correlation-causation second nature to things in real life.

So my daughter (who is two and a half) and I were standing in our balcony this evening, observing that it had rained heavily last night. Heavy rain reminded my daughter of this time when we had visited a particular aunt last week – she clearly remembered watching the heavy rain from this aunt’s window. Perhaps none of our other visits to this aunt’s house really registered in the daughter’s imagination (it’s barely two months since we returned to Bangalore, so admittedly there aren’t that many data points), so this aunt’s house is inextricably linked in her mind to rain.

And this evening because she wanted it to rain heavily again, the daughter suggested that we go visit this aunt once again. “We’ll go to Inna Ajji’s house and then it will start raining”, she kept saying. “Yes, it rained the last time it went there, but it was random. It wasn’t because we went there”, I kept saying. It wasn’t easy to explain it.

You know when you are about to have a kid you develop visions of how you’ll bring her up, and what you’ll teach her, and what she’ll say to “jack” the world. Back then I’d decided that I’d teach my yet-unborn daughter that “correlation does not imply causation” and she could use it use it against “elders” who were telling her absurd stuff.

I hadn’t imagined that mistaking correlation for causation is so fundamental to human nature that it would be a fairly difficult task to actually teach my daughter that correlation does not imply causation! Hopefully in the next one year I can convince her.

## Shouting, Jumping and Peacock Feathers

The daughter has been ill for nearly the last two weeks, struck by one bacterium after one virus, with a short gap in between. Through her first illness (a stomach bug), she had remained cheerful and happy. And when I had taken her to hospital, she had responded by trying to climb up an abacus they had placed there in the children’s urgent care room.

So when the virus passed and she recovered, the transition was a rather smooth one. The day after she recovered I took her to the park where she jumped and ran around and rode the swing and the slide. Within a day or two after that she was eating normally, and we thought she had recovered.

Only for a bacterium to hit her and lay her low with a throat infection and fever. Perhaps being a stronger creature than the earlier virus, or maybe because it was the second illness in the space of a week, this one really laid her low. She quickly became weak, and rather than responding to “how are you?” with her usual cheerful “I’m good!!”, she started responding with a weak “I’m tired”. As the infection grew worse, she stopped eating, which made her weaker and her fever worse. Ultimately, a trip to the doctor and a course of antibiotics was necessary.

It was only yesterday that she started eating without a fuss (evidently, the antibiotic had started to do its work), and when she made a real fuss about eating her curd rice last night, I was deeply sceptical about how she would get on at her nursery today.

As it happened, she was completely fine, and had eaten all her meals at the nursery in full. And when I got her home in the evening, it seemed like she was fully alright.

She is normally a mildly naughty and loud kid, but today she seemed to make an extra effort in monkeying around. She discovered a new game of jumping off the edge of the sofa on to a pillow placed alongside – a sort of dangerous one that kept us on the edge of our seats. And periodically she would run around quickly and scream at the top of her voice.

To me, this was like a peacock’s feathers – by wasting her energy in unnecessary activities such as jumping and screaming, the daughter was (I think) trying to signal that she had completely recovered from her illness, and that she now had excess energy that she could expend in useless activities.

The upside of all this monkeying around was that soon after I had helped her get through 2-3 books post her dinner, she declared that it was “taachi (sleep) time”, and soon enough was fast asleep. This is significant in that the last few days when she spent all the time at home, her sleep schedule had gotten ruined.

## Once upon a time

Thanks to gifts from various sources (including the National Health Service, where we’d gone for a checkup), Berry has a few books now. Most of them have lots of pictures (the only book we’ve bought for her is simply a collection of animal pictures). Some have text as well. And it is that that is rather underwhelming.

I don’t know the target age group for most of these books, but the stories seem damn lame to Pinky and me. In my opinion, a good children’s book (or show) should not only be interesting for the child, but also for the parents – it is not often that the child uses the book or show alone. And from that perspective, a lot of these books Berry has got don’t pass the muster.

The books I had when I was a kid may not have been particularly optimised for a child. The illustrations weren’t great. The paper quality was underwhelming as well (one thing Berry can’t do with her books is to tear them! A useful quality for sure for children’s books). But the stories were fantastic. And things that I still remember.

Most of these stories came from the Panchatantra, which is a collection that “evolved” over time. This memetic evolution means that the stories that have come till today are “fit”, and fantastic. It’s similar with Aesop’s Fables – their age means that stories have evolved sufficiently to become damn interesting. And of course, this applies to the Ramayana and Mahabharata as well (and NOT to Christian myth, which didn’t get time to evolve and is thus rather boring).

Speaking of myth, I recently read Neil Gaiman’s book on Norse Mythology.  It’s a good book, and I’ll make Berry read it before she is five. But the stories themselves were all rather underwhelming and devoid of complexity. Considering it’s an ancient myth, which had sufficient time to evolve being written down, the simplicity of plots is rather surprising. Or maybe it’s the way Gaiman told the story.

I’m reminded of this “one Shloka Ramayana” that I’d been made to mug up as a kid (I still remember it “by heart”. Maybe Gaiman’s book is the Norse equivalent of this?

Hatva Mrigam Kanchanam
Vaidehi Haranam, Jataayu Maranam
Sugreeva Sambhashanam

Bali Nigrahanam, Samudra Tharanam
Lankapuri Dahanam,
Ethat Ithi Ramayanam

In any case, considering the lack of plots in “modern” children’s books, we’re seriously exploring the idea of bringing back truckloads of Amar Chitra Katha when we visit India later this year.

## Relative size of hand and mouth

So the daughter and I are playing a game where she makes a gesture and I try to imitate it (this blogpost is not part of the game, of course). Like me, and my mother before me, she’s an expert in contorting her face in all kinds of ways. So it is a fun game, to try and imitate each other in the way we contort faces.

One thing she does which I’m thoroughly incapable of replicating, however, is putting hands in mouth. She seems well capable of inserting her whole hand inside her mouth. On the other hand I struggle to even put in a finger or two.

This makes me wonder about the relative growth patterns in hands and mouths. As a baby, we are born with big heads and faces, and consequently big mouths. Limbs are tiny in comparison. As we grow, though, our limbs grow much faster than our heads, to the effect that soon we become incapable of putting hands in our mouths, and at best, can just suck on a thumb!

Another thing I’ve noticed in my daughter’s growing up is that she seems thoroughly incapable of putting her big toes in her mouth. It’s a well documented fact (with photos) that I used to do a fair amount of this as a baby. Even now, with some effort I can bring around my big toe and can suck on it if I want to. The daughter, however, seems thoroughly incapable of doing that.

Conventional wisdom is that as we grow older our bodies become less flexible. I wonder if it’s actually a curve that first increases, hits a maximum and then decreases slowly through life. So maybe my daughter can’t suck on her big toe because she’s too small for it (she’s three months old now)!

Whatever it is, it’s fascinating to watch babies grow!

## Avatars

This is regarding the Avatars of Vishnu.  It is quite fascinating how Buddha managed to enter the list (he is number 9 on the list). Apparently a number of communities give that spot to Balarama (Krishna’s brother), notably Iyengars and other Vaishnavite communities. I have also seen this in a few temples (don’t know which “denomination” (if such a thing exists in Hinduism) these temples belong to) which have Balarama as #9.

The most popular explanation (which I have no reason to disagree with) about the Buddha’s entry into the list is that it was a clever ploy to prevent the spread of Buddhism, which threatened to become the largest religion in the subcontinent in the few centuries before and after christ. By including Buddha in the Hindu Pantheon, and by declaring him to be an avatar of Vishnu, an attempt was made to describe Buddhism as just a branch of Hinduism. Looking at the way Buddhism has developed after that in the subcontinent, I have reason to believe that the ploy was successful.

Regarding the construction of the list, there are again two possibilities. One view says that it was constructed not more than two millenia ago, and it was constructed only as a response to Buddhism. That it was something like “Ok here is the Buddha. He threatens us. So let’s make him one of ours. Let us declare him to be an Avatar of Vishnu. But then, we need more avatars to make this look credible. Let us include evolution into this and put in a few animals, etc. and have a nice list. But we have only 9, and there is no logical person who can finish this list. So let’s assume that he will happen sometime in the future, when the world ends. So here is The List”.

The other possibility is that one such list already existed, and the Buddha was included in the list. Though 8 is not an inauspicious number, it is unlikley that there were originally 8 avatars. Which means that there were originally 10, including possibly Kalki, and the Buddha replaced one of these 10. Looking at the other popular version of the Dashavatara, it is likely that the Buddha replaced Balarama in the list.

This raises a couple of interesting questions:

• What avatarish thing did Balarama achieve in order to be an avatar? Which demon did he kill? I only recall him being mentioned fleetingly in the early stages of the Mahabharata, and he walked away from the war later on. So what message did he carry?
• Balarama being an avatar, and his being a brother of another avatar Krishna, means that two avatars coexisted. In fact, someone on the list pointed out that Parashurama is a Chiranjeevi, so he has coexisted with all avatars following him. So we need to dissociate the avatar concept from the concept of rebirth and reincarnation. In any case, fascinating stuff
• It is remarkable that Hinduism was flexible and nimble enough to turn the Buddha into an avatar when they saw him threaten them. The presence of mind of the people who thought of this workaround is commendable. I wonder where Hinduism lost its flexibility after that.
• I also wonder how this was implemented. Hinduism has no supreme leader. And in the days when the Buddha was included into the list, there wasn’t even a Postal system, leave alone conference call facilities. How did this idea spread and gain enough credence to become the norm, then? Where did this idea of making the Buddha an avatar originate? How did t hey disseminate it? Who was the powerful set of people who were instrumental in the design, development and distribution of this idea?