woensdag 17 oktober 2018

On Echo Chambers, Statistical Principles, Vaccinations and Autism

The Centuries Old Vaccination Debate
The 'vaccination debate' is as old as the introduction of the first vaccinations in the eighteenth century. A minority of anti vaccinationists rejected vaccinations with 4 main arguments, which have stayed remarkably the same over the centuries: 1) vaccinations cause all kinds of harm (syphilis, measles, encephalitis, autism, death, et cetera, depending on the time period); 2) vaccinations are unnatural; 3) vaccinations are against God's predestination; 4) vaccinations are forced upon us by Edward Jenner/the pharmaceutical industry to earn profit.[1]

Unfortunately, in the twentyfirst century anti vaccinationists are winning ground and vaccination rates are dropping. This causes a global public health risk.  The anti-vaccination lobby would not be so successful if more people had a better grasp of vaccination history, basic causality, communication science and statistics.[2]  As a historian, a 'data scientist' and a father I will argue why the idea that vaccinations cause all kinds of bad side effects, most notably autism, is a dangerous myth.  If you are convinced vaccinations cause harm I do not have much faith in changing your mind, even if you are still reading, unless you keep an open mind. This blog is mostly for people who are in doubt, or are not sure what to think. Or for people who are not in doubt but want to use more solid arguments against anti vaccinationists. I will demonstrate that even though it is very understandable people still think vaccinations cause harm, there is no basis in facts or logic to do so.

Echo Chambers and Confirmation Bias
In this century the vaccination debate has found its way to online communities, where it has been carried on with increased intensity.[3] Despite irrefutable scientific evidence to the contrary, an alarming number of people are convinced that vaccinations cause autism or other unwanted side effects. This at least has partly to do with the online world facilitating the easy creation of new 'echo chambers'. Echo chambers are sealed off (metaphorical) spaces in which like minded people find each other and confirm each other in their beliefs. In earlier times echo chambers were mostly formed in small communities, but in the online world they can integrate people from all over the world. The internet also facilitates the availability of all kinds of information. It is human to read and believe the information that confirms what you already know, even if it is contradicted by many more, and better substantiated, sources. When people lock themselves up in Echo Chambers where one sided information is spread among like minded individuals it even can seem as if the majority of the population think like they do. Any information that says the contrary can likewise be easily dismissed.[4]

The Outliers have more impact on public perception
It is highly unlikely, yet still possible, that a vaccination causes an unwanted side effect. Still, stories of the failures are the ones that spread rapidly. You rarely hear someone saying a vaccination went perfectly, for the simple reason that it is not really something special to report. If something, supposedly, goes wrong people are far more likely to share their story. This is why the outliers, the results that are most unlike regular results, have more impact. If 1 in 10.000 vaccinations have some kind of bad side effect this potentially has much more influence on public perception than the 9.999 vaccinations that went just fine. Already in the nineteenth century anti vaccinationists often had a few horror stories ready to scare parents into not vaccinating. Since the (online) world is a big place the number of scary experiences can go up quickly, even if relatively speaking the number is still small and insignificant. A case file of a hundred 'horror stories' can serve as a scary deterrent for young parents to vaccinate.

Sometimes we have to accept we do not know or can not influence the cause
Something else which is human, is the compulsive need to understand the world and to be able to influence what is going on. In earlier centuries when a harvest failed it was the work of the devil, or a witch, or a punishment from God. You could try to improve your fate by burning the witch or by praying. A simple 'bad luck' with the weather conditions is more difficult to accept, since you cannot do much about that as an individual. No one likes to be a helpless victim of 'dumb bad luck'. Still, sometimes we have to accept this.

Just because B follows A does not mean A caused B
The difficulty to accept being helpless also is part of the reason that the link between vaccinations and autism is so persistent. It is unknown why one child is autistic and the other is not, except that it seems to have something to do with genetics. Vaccinations are scary, because it is difficult to understand what you are really injecting into your child. If your child also becomes 'visibly autistic' around age two, shortly after it received its second MMR vaccination, it is natural to think of a causal relation between something scary and something inexplicable. Human instincts are still very 'medieval'. For inexplicable phenomena people look for unlikely causes to channel their feelings of fear and helplessness. This feeling can be stronger than solid evidence that there is no causal relation between autism and vaccinations, and the exposure of the first scientist who made this claim as a fraud. [5]

Within a mass of big data there are no regular patterns
It also is important to realise that data do not follow any regular patterns. Statistics quickly can seem false if your own perceptions show a completely different pattern. Imagine that according to statistics 1 in 1000 children gets a high fever after being vaccinated, but that in your near surroundings you already know three children who were struck with high fevers. It is easy to think that the numbers should be 1 in 10 instead of 1 in 1000. The study must be flawed or maybe the government has made it up! It would however be extremely unlikely, even if all the other circumstances were the same, that a statistical pattern is regular. For many professors this knowledge even is a way to quickly spot badly falsified data. A normal pattern is not A, B, C, D, E, A, B, C, D, E, but the more random A, A, A, C, E, A, A, B, A. Results clump together, which is why many gamblers can think they are in a 'winning streak'. It however is not a winning streak, but a normal result within the advertised odds of winning or losing. Every gamble has the same chance of success, regardless of the gambler having won or lost ten times before the current gamble.

Measuring more does not mean there is more than before
It does not help that autism seems to be a modern phenomenon. People therefore try to blame modern vaccinations and changes in the environment or even food patterns. It is true that an increasing number of people are diagnosed with autism. This does not (necessarily) mean more people are autistic than before. The 'elf children', 'eccentric uncles' or 'siblings in the lunatic asylum' from centuries gone by would now get a diagnosis of an Autism Spectrum Disorder (ASD).  Over the past decades, the definition of autism also has been extended to include many more variations than before. To give one extreme example: not so long ago doctors could claim that only boys were autistic. Obviously the number of diagnoses will go up when you start including the other half of the earth's population as possible candidates as well. It also is more difficult for people on the spectrum to go 'unnoticed'. Modern society likes to measure, quantify and categorise everything. Furthermore, and far more damaging, modern society subjects people to many difficult-to-channel impulses. One may wonder if brilliant minds of the past who may have been on the spectrum, like Mozart, Darwin and Einstein, could have flourished in the 21st century like they did in their own time.

Even if all of this was not true, and vaccinations indeed cause autism, why would any parent prefer to have a child die from measles or polio over having an autistic child?

[1] D. Porter and R. Porter. 1998. The politics of prevention: anti-vaccinationism and public health in nineteenth century EnglandMedical History, 32:231–252; C. E. Daniels. 1875. De kinderpokinenting in Nederland: meerendeels naar onuitgegeven bescheiden bew- erkt: eene medisch-historische studie. Amsterdam.; W. Rutten. 1997. De vreselijkste aller harpijen. Pokkenepidemieen en pokkenbestrijding in Nederland in de 18e en 19e eeuw. Universiteit Wageningen.
[2 I thank my basic understanding of statistics to Statistic Reasoning for Everyday Life by Bennett, Briggs and Triola.
[3] Ana Lucia Schmidt, Fabiana Zollo Antonio Scala, Cornelia Betsch, and Walter Quattrociocchi. 2018. Polarization of the vaccination debate on FacebookVaccine, 36:3606–3612
[4]T. Chamorro-Premuzic. 13 May 2014. How the web distorts reality and impairs our judgement skills. The Guardian; M. del Vicario, G. Vivaldo, A. Bessi, F. Zollo, A. Scala, G. Caldarelli, and W. Quattrociocchi. 2016. Echo chambers: Emotional contagion and group polarization on FacebookSCIENTIFIC REPORTS, 6, 37825

dinsdag 4 september 2018

Big Data and Autism - A Metaphorical Link

For the past six years I have been working in the field of Digital Humanities, trying to make sense of ‘big data’ for humanities research with computational methods. Exploring the possibilities and limitations, to seek out new methodologies and basically to go where no humanist has gone before.

For the past six years I also have been the father of a daughter, Anna, with autism. What I have been doing professionally she has been doing her entire life: trying to make sense of the ‘big data’ in her head with the methods she has at her disposal.

It is difficult to define what autism is. It is a spectrum with many symptoms, and individuals on the spectrum will be affected differently. For me it helps the most to think of autism as an ‘information processing disorder’. People with autism, or people with ASD (autism spectrum disorder),  see and view the world fundamentally differently than people without. Often they have trouble filtering information and sounds, which can make the outside world an overwhelming place. This filtering of information and data also can be a problem for the processes taking place in the heads of people with autism. It is difficult to find the right piece of data for every situation, turn it into useful information and knowledge and use that in a practical way. As a consequence, some people with autism barely speak, or are even completely mute. Others do the opposite and will rant endlessly to compensate. Others do both. Some do not speak, but do read and write. People with autism can therefore be very present, or completely silent. People with autism often have difficulty functioning in modern society, with its fast pace and many daily impulses. Autism should, however, be considered as a variety, not as a disability, and most certainly not as a desease. Many people with an autistic brain can function well, some would say even better, if circumstances allow it. Some of the greatest minds in history, like Mozart, Darwin and Einstein, may have had autism. Some people with autism are disabled, because they cannot function in society on their own. Most, however, just function differently. Only time will tell how ‘severe’ my daughter Anna’s autism will continue to be. She does not speak normally; sometimes she does not speak at all; at this point there is no way of knowing if she will ever function (properly) in society; if she will ever know romantic love; if she will able to cope with the loss of loved ones; if she will ever deal with her neurotypical brother on equal terms; if she can ever live on her own. At this point there is no greater fear in my life than the thought that she will die alone in some kind of nursing home, frustrated and misunderstood, thirty years after me and my wife are gone.  

Coming back to the Big Data Metaphor: when looking at Anna I often wish I could know what she is thinking. And I often wish I could make sense of the ‘big data’ in her brain. It’s like there is a barrier in Anna’s head, which makes it difficult to make sense of all the pieces of data. We do not know how ‘big’ the data in her head is, but we suspect it is big. She was extremely fast as a baby to learn words, phrases, songs, et cetera. Ironically it looked like she would be able to speak well ahead of her age. This changed when her autism stopped her from channeling all the data in her head into speech, when she was around two years old.  It is therefore likely that since that time she has amassed a huge pile of ‘big data’ that begs to be sorted, categorised, and, most importantly, translated into useful information and knowledge.

Some pieces of data are easy to find for Anna. Especially colours. She can play happily with a yellow ball while repeating ‘the yellow, the yellow’. Sometimes she even refers to me and my wife with the colour of clothes we are wearing. When she is searching for a toy she can continue repeating ‘Does Anna want the blue, does Anna want the blue’.  Making me and my wife desperate in repeatedly asking her ‘the blue what, Anna?’ Anna knows the word of the item she is looking for, but it causes her visible pain to delve deeper into her brain and find and use this piece of data.

At times Anna taps into more data to describe a situation, and very rarely this even makes her sound almost neurotypical. Anna’s biggest problem may be grasping the link between words and having a ‘normal’ conversation. She uses the big data in her head to let us know what she wants, or needs. If a child in the playground tries to strike a conversation with her, she stays mute, unable to respond well to an unexpected query in a different setting from an unknown person.

Anna’s problems with dealing with the big data in her head makes her attached to the structures she does know in her life. When we prepare her to go to ‘school’ she knows she has to take the bus to go there. When we walk to the car on Sunday she knows we will do grocery shopping. When we take the car on another day she knows we may do something fun, like going to her grandparents, or to an amusement park or petting zoo. If something does not go according to what she expects, a little drama can unfold. If, for example, we drive in grandfather’s direction but go somewhere else she will protest. If we cannot eat french fries for lunch when ‘going out’ she will protest (even in a pancake house).

As a researcher it is my duty to try to do proper and conscientious research with big humanities data. As a parent it is my duty to try to hand Anna the algorithms to make sense of the big data in her head. The metaphor can be carried on to quite some extend: Some things are easy to find with the algorithms, like colours, while others seem to be unattainable at the moment. If something unexpected happens the algorithm will fail. Sometimes we have to accept a less than optimal result. Sometimes we only are able to scrape data, without getting any information or knowledge. And we always should be aware that maybe for some things we have already reached the summit of what we can achieve.

Fortunately Anna has one advantage to help her out: the human mind is wonderful and powerful. An algorithm or methodology for humanities research can only be improved by the researchers. Anna’s mind is a processing pipeline that she will continue to improve over time. That way she may be able herself to find the proper pathways to make sense of the big data in her head and translate it into information, knowledge and eventually communication. Time will tell.