In defence of anecdotal evidence

Anecdotal evidence is worthless, right? It comes about through uncontrolled conditions, and the people reporting it may report selectively (whether or not they intend to be biased). Thanks in part to the works of writers such as Richard Dawkins, we have learnt to dismiss anecdotes and personal testimonials, bringing us closer towards a world governed by Reason and statistics. And we can consign anything supported merely by anecdotes to fire. Hurrah!

For many things in the natural world, it is relatively straightforward (if expensive) to isolate the thing to be tested, conduct experiments or controlled trials, and then quantify the effect of that thing, with well-defined error bars. There are well-established principles and procedures for designing clinical trials, which is why we can resolutely label things like homeopathy, claims about the MMR vaccine, and everything Deepak Chopra says as bullshit, even if there are occasional success stories.

But – and perhaps Dawkins and co. haven’t realised this yet – humans are complicated, and social phenomena, which involve multiple humans, are very complicated. It is impossible to control the environment in which they arise. Also, individual experiences are unique, and it is difficult to give meaningful definitions or boundaries (see also this post), and to ensure that everybody uses the same definition. Related to this, people do not always accurately report their experiences: something that is perceived to be ‘shameful’ will be underreported even if it is actually quite common.

For these reasons, many social phenomena have not been studied quantitatively. But

Absence of evidence is not evidence of absence.

If anything, it is evidence that you haven’t yet done a good enough job collecting evidence on the subject.

When nothing else is available, and when it is not possible to conduct a systematic, controlled and quantitative study, then anecdotal evidence is the best you can do, and it needs to be taken into account, provided it comes from a credible reporter, who has no vested interests. And you must hear that evidence, even if you do not give it much weight.

In more technical language, I am arguing that probabilities are subjective measures of a degree of belief, not objective, and that any evidence should update your posterior probability, even if not by very much.

What I’ve said so far has been relatively abstract, but a failure to understand this has truly harmful effects when we dismiss anecdotal evidence. When hundreds of people report that they have been victims of something, then we need to start taking their testimonials seriously.

The Everyday Sexism Project has collected reports from tens of thousands of women about the sexist abuses that they have suffered. These are idiosyncratic and can’t be categorised; they might have happened repeatedly over a long time, or be one-off events. These acts are often not visible: even the person doing or saying the sexist things might not realise that they are being hostile. An individual claim of sexism might be dismissed by suggesting a variety of mitigating circumstances, or even by assuming bad faith on the part of the reporter! But what is more likely: that misogyny exists in our society, or that thousands of women have conspired together to make up that myth? (You may find Occam’s razor useful.)

Everyday sexism is just one example of microaggression, which also happens in other contexts such as race and religion. Moreover the fear of being subject to a racist attack is just as relevant as the number of actual attacks. Fear has a chilling effect on society, and has a measurable effect on the economy, but by its very nature it is difficult to measure.

Other examples include people’s testimonials of an NHS (or other public service) that is unable to provide a good experience. When thousands of people across the country complain about this, then it is no longer an egotistic individual or a problematic local service; there is something nationwide happening.

In summary,

When thousands of anecdotes are given, then it is no longer "merely" anecdotal evidence.

As with the etymological fallacy, the failure to give anecdotal evidence the weight that it sometimes deserves is a dangerous fallacy, because it is easy to commit it, thinking that you are rational and your opponent is not. This arrogant attitude poisons a discussion.

British Independence Day

Some Brexiters have suggested that June 23rd should become celebrated as Britain’s Independence Day. Simon Richards, head of the so-called ‘Freedom Association’ and a prominent Brexit campaigner, justified this just now on Radio 4. Apparently, Britain needs a national day to bring its people together. The fact that Brits don’t have such a day apparently makes us jealous of Indians and the African nations who all have national days of independence!

The etymological fallacy and related crimes

One of the argument techniques that I found most frustrating is the etymological fallacy, the idea that the meaning of a word or a symbol is determined completely by its origin, with no regard to its current usage or the particular context of the conversation. It is related to another common fallacy, which is to give a word a non-standard definition and then not sticking to that definition.

Like most fallacies, it is employed by people on all sides of an issue (and I welcome any further examples that you can think of). Etymological fallacies are often committed by self-identifying ‘rational’ people, who otherwise delight in picking flaws in other people’s reasoning. These people tend to see the world in black-and-white terms, and perhaps think that their arguments are impervious to criticism because they take an axiomatic approach. Such an attitude is nothing more than a cousin of Biblical literalism.

(Aside: Think of Professor Dawkins. Even their use of the self-label ‘rational’ is an example of the fallacy in action. I might rant some more about so-called ‘rationalists’ in the future. In the meantime, here is a caricature.)

The etymological fallacy does not only helps one invalidly arrive at a conclusion. What makes it particularly frustrating is that it can also shut down conversation completely. It is not possible to have conversations about complicated issues when the terminology are restricted to narrow definitions.

On the other hand, claiming that one uses words and symbols only according to their literal meanings is particularly insidious, because it is used to appeal to racists, without explicitly admitting that one is a racist. As such, it is a form of dog-whistling.

Continue reading The etymological fallacy and related crimes

Spreading the system

A new postdoc arrived in our lab this week, having come from China. In a one-party state that has such a strong control over its media, it’s unsurprising that he didn’t even know that an election was happening here, and he spent yesterday learning about the system. It’s a flawed system, but if the very act of holding an election means that people from countries like China are awakened to its workings and its benefits, then that is in itself a good thing, even if Theresa May did call it for dodgy reasons.

Some people complain of ‘election fatigue’, but we should take a step back and realise the privileged position that they are in, compared to billions of other people around the world.

Theresa’s pre-election patter song

Enter THERESA and chorus.

I seek power that your human rights I may impale,
And all th’intimate details of your life surveil,
Should the alt-right need placation, ban the Muslim veil,
And I’ll do this with the backing of the Daily Mail!

Yes she’ll do this with the backing of the Daily Mail!

That my Brexiteering actions shall not be derailed
We’ll lock saboteurs and judges in a trial-less jail.
Sans their nauseous interventions Britain shall prevail!
And we’ll do this in the name of the Daily Mail!

May she do this in the name of the Daily Mail!

If you hesitate to stop us, and we do not fail,
We will privatise the air and you will pay to inhale.
Yes the years to come will be quite a living Hell,
But I do this for the readers of the Daily Mail!

Yes she does this for the readers of the Daily Mail!


Tories or Star Wars?

Which of the following are quotations of Theresa May, and which are from Star Wars?

  • ‘Only through me can you achieve the power greater than any {Jedi|other country}.’
  • ‘Unelected members of the {Jedi Council|House of Lords} have vowed to fight us every step of the way.’
  • ‘Fear will keep {the local systems|potential extremists} in line.’
  • ‘The last vestiges of the {old Republic|European Union} have been swept away.’
  • ‘I will make it legal.’
  • ‘In order to ensure {security|stength} and continuing {prosperity|stability}…’
  • ‘Don’t continue to be a pawn of the {Jedi Council|Labour Party}!’
  • ‘At this moment of enormous {galactic|national} significance there should be unity here in {the Senate|Westminster}. But instead there is division. The {Galaxy|country} is coming together but {the Senate|Westminster} is not.’
  • ‘…for a {safe and secure|strong and stable} society!’
  • ‘I love democracy.’
  • ‘I was right! The {Jedi|saboteurs} are taking over!’
  • You have lost!’
  • ‘Every vote for {emergency powers|the Conservatives} will make me stronger.’
  • ‘Once more, the {Sith|Conservatives} will rule the {Galaxy|country}. And we shall have peace.’
  • ‘You will pay the price for your lack of vision!’

The Fourth of June: Hong Kong and the UK election

Today is the anniversary of the Tiananmen Square Massacre, which took place in Beijing in 1989. The Chinese government estimates that 200 people died that night. The true number is almost certainly an order of magnitude higher. To this day, the Chinese government continues to deny the simple fact that the protests even happened, and doubles its efforts to suppress attempts to remember it each anniversary, although remembrance demonstrations are permitted in Hong Kong.

Protestors in Hong Kong’s Victoria Park on 4 June 2017. Photo: Larry Au

Margaret Thatcher issued a strongly worded statement at the time criticising the massacre. She did little else. In 1984 she had signed the Sino–British Joint Declaration, which would set the scene for Hong Kong’s transfer of sovereignty from Britain to China in 1997; in return, China had to promise that she would look after Hong Kong really, really well and allow autonomy under the principle of ‘One country, two systems‘. The handover went ahead as planned, even after the world saw the true face of the Chinese regime: one not unlike the Soviets, who invaded Hungary in 1956.

Tank Man
Tank Man, an iconic photograph of a lone protestor standing in front of a column of tanks. Photo: Jeff Widener, Associated Press

Britain asked no questions as she handed over seven million people. And, despite increasingly frequent and increasingly large-scale protests in the former colony, she remains quiet. No economic sanctions against China have ever been considered, even as the latter continues to infringe upon Hong Kong’s civil liberties, in direct violation of the Sino–British Joint Declaration. The Cantonese language is slowly being replaced, as is the Traditional Chinese script. David Cameron and George Osborne continued to kowtow to China’s leaders in the hope of obtaining Chinese investment for Britain. British nationals were abducted by Chinese agents, and they did little about it other than grumbling indignantly in an ever-so-British way.

What does this have to do with the upcoming UK election?

Whoever forms the new UK government later this week should hold China to the terms of the Sino–British Joint Declaration, as well as its human rights obligations more generally. The new British Prime Minister should be prepared to criticise and not to kowtow. How Brexit will play out precisely is unknown, but Britain must continue to work together with the rest of Europe in order to have the power to impose meaningful economic sanctions against China. Since 1989, the EU has banned arms sales to China; post-Brexit Britain should not resume these in exchange for Chinese cash.

Britain fiercely defended the Falklands against the 1982 Argentinian invasion, and continues to reject foreign claims to the Falklands and to Gibraltar, based on the principle that the locals have the right to self-determination. Hong Kong deserves as much. And this is not just for the sake of the Hong Kong people: What message would it send to the world if Britain simply allows a treaty to be broken, with no consequences? Would that be a good position in which to start negotiating trade deals after Brexit?

Unsurprisingly, Hong Kong and China are not major talking points in this election, but how the next British government responds to the China’s continued human rights abuses, both on its mainland and in Hong Kong, could define Britain’s place in the post-imperial world for decades to come.