mandag 24. januar 2011

More about irrationality

Hi,

Today's post is about a piece of writing that I don't really recommend: A report from the French Food Safety Agency called



This report is a splendid example of irrational "scientific" thinking: Intelligent people following what they consider good rules, and ending up with a completely ridiculous result. If you take the logic of the of this report seriously, it would be wrong of health care personell to give mouth-to-mouth first aid to victims of drowning today:


a) The method carries with it several risk factors, like blowing air into the patient's stomach, which can cause the patient to vomit and get gastric acid into his airways. The method also carries with it the risk of over-inflation and lung damage, particularly if the patient is a child with low lung capacity. Heart compressions, which are often advocated along with the blowing, carry with them a severe risk of fractured ribs.

b) No double-blind study has yet been done, where drowned patients have been randomly been assigned to the treatment group and placebo group, and where enough care has been taken to keep observers in the dark about what patient is getting mouth-to-mouth treatment and who's been given placebo.


Before I get back to the drowning victims, I'd like to say something about seven distinct types of irrationality that we may be dealing with here.

1) First and foremost, the authors of this report seem to be suffering from a severe case of irrational loss aversion.
This factor was first convincingly demonstrated by Amos Tversky and Daniel Kahneman. Several studies have shown that the motivating force of a potential loss (like the social awkwardness from being on a diet) is much stronger than a corresponding gain (like recovering from autism). This is sometimes also called the pseudocertainty effect – the tendency to make risk-averse choices if the expected outcome is positive, but make risk-seeking choices to avoid negative outcomes.


* On the one hand, they are taking very seriously a small risk for a modestly negative outcome: "No data are available on growth or nutritional status of autistic children subjected to a gluten-free, casein-free diet. Therefore, it is impossible to contend that such a diet has no harmful effect in the short, medium or long term".

* On the other hand, they are completely disregarding the possibility of a positive outcome.

2) Secondly, it seems safe to guess is that the loss aversion in this case is being reinforced by omission bias – the tendency to judge harmful actions as worse, or less moral, than equally harmful omissions (inactions).

* The alternative they are advising against, requires practical action.

* The alternative that they don't mind, consists of inaction.

3) Thirdly, the way the authors justify their position makes me suspect that they also suffer from the observer expectancy effect – they may have manipulated unconsciously the criteria for what they consider valid, in order to find the result they expected.


* On the one hand, they advise that studies should be assigned a credibility of zero, unless they fulfill certain formal criteria: A control group (autistic children without dietary intervention), random allocation of treatment or placebo, and a double blind protocol. These criteria happen to exclude all evidence for an effect from diet on autism.

* On the other hand, this last study is assigned high credibility, in spite of the fact that the study design is such that it didn't actually test the hypothesis that most parents and supporters believe in. It's as if they'd finally gotten around to doing a double-blind placebo-controlled study of mouth-to-mouth resuscitation, ... and were giving the patients 2 inhalations each, without clearing their airways of water first.

4) Fourth, they also seem to have been at risk of falling for the Ambiguity effect - the tendency to avoid options for which missing information makes the probability seem "unknown." I see this as a verision of the Zero-risk bias - the preference for reducing a small risk to zero over a reduction in a larger risk).


* In autism, the total amount of uncertainty will be reduced if nothing is done (although in favour of a truly awful outcome).

5) Fifth, the authors must also have been at risk of
Hyperbolic discounting - the risk of having a stronger preference for or against something, the closer to the present the cost or payoff are in time or space.


* In autism, the cost of treatment (financial and in the form of hassle) is certain and immediate, while the benefit is uncertain and several months (years) into the future.

6) Sixth, the authors have also been at risk for the Bandwagon effect the tendency to do or believe things because many other people do or believe the same. This is related to "groupthink", "herd behavior" and the Semmelweis reflex – the tendency to reject new evidence that contradicts an established paradigm and the Availability cascade - a self-reinforcing process in which a collective belief gains more and more plausibility through its increasing repetition in public discourse (or "repeat something long enough and it will become true").


* No medical authorities have yet had the courage to be the first to make a rational cost-risk-benefit analysis of what this treatment has to offer autistic children.

7) Lastly, it's also possible that the authors (or the authority figures that have created today's medical paradigm in this area) are suffering from
Confirmation bias – the tendency to search for or interpret information in a way that confirms one's preconceptions. This factor will be particularly strong if the preconceptions in question have the power cause severe and irreparable damage.


* In autism, it can be postulated that the medical authorities will be less and less disposed towards changing their policy, the more children that have suffered irreparable brain damage as a result of those policies.

There is probably a strong synergistic interaction between all these kinds of irrationality.

Now, back to the drowning victims. Do I hear voices saying that it's unethical not to treat them with whatever means we have at hand, as long as there's a chance that we might save them?` Thank you very much. That's exactly my point. Why shouldn't the same rule be applied to autistic children? Untreated autism leaves the patient to suffer for a lifetime (irreversible brain damage), along with his parents (burned-out), his siblings (neglected), and the rest of society (stuck with the bill when the patient grows up).

We still have a chance of saving at least some of these children. Why are these people insisting that we don't even try?



- o 0 o -

Before you can say you have a rational solution to the autism-and-diet question, you need to do the math involved in a structured risk analysis. I recommend that everyone who is interested in this issue, start by setting up a risk analysis matrix around at least five risk factors:


1) The patient 's physical growth is retarded because of a well monitored GFCF diet,
2) The patient develops irreversible brain damage, from untreated autism
3) The patient's social life becomes more complicated because of a GFCF diet,
4) The patient's social life becomes more complicated because of autism
5) The patient's parents incur some expense because of the GFCF diet,

They should then assign a probability of 1-100% to each of these factors, under the following alternatives:


a) The patient does not try the diet.
b) The patient tries the diet, has no effect from it, and discontinues it after 6 months.
c) The patient tries the diet, experiences an average *) reduction in symptoms, and continues.
d) The patient tries the diet and recovers completely.

*) The average outcome of dietary experiments is still unknown. Even if it were known, it would be impossible to extrapolate from that figure to what was going to happen to one specific patient. For that patient, the full range of outcomes must still be reckoned with, from nothing to a full recovery. The actual treatment decision must therefore always be based on possibilities, rather than probabilities. Even so, I've attempted to assign a value to this column, based on my best assessment of the total amount of evidence available.

Next, they should assigned a numerical value (for example 1-100) for the importance of each of the problems above, relative to the worst possible outcome in the most serious of the categories, to make them comparable.

Lastly they should multiply probability and importance. The resulting numbers will tell something about how important you consider it is to guard against each of these factors.

My conclusion at the bottom of my personal risk analysis matrix, was that a lifelong diet needed to produce a recovery rate of around 4%, or a reduction in severity of the autistic outcome of the same size order, in order to outweigh the costs. If we take into consideration that patiens who don't benefit from the diet, can discontinue it after 6 months, the figure falls to under 1%.

This is all based on my personal value system, i.e. how I (for example) prioritize a 100% certain loss of social convenience (being able to eat anything in birthday parties) versus a somewhat lower chance of irreversible brain damage.


I'm longing for the day when the Government's medical researchers starts doing this kind of math. When they come clean about their priorities. When they start looking at ALL the available evidence, including the lab reports that show the opoid peptides right there, physically present in the blood and urine ... just because it isn't part of a randomized double-blind placebo controlled crossover study.

And I'm longing for the day when the same people start paying attention to study designs, and start laughing - along with me - of studies that are so badly designed that they can't prove anything - even though they fulfill all those sensible criteria, with randomization and crossover and all.

:-J

onsdag 19. januar 2011

IQ and rationality

I'm reading about the distinction between intelligence and rationality these days:

What Intelligence Tests Miss: The Psychology of Rational Thought

There's one aspect of the book that I'd like to comment on so far:

Intelligence has to do with the processing power of the brain. Rationality has to do with how we form our beliefs.

In other (my) words: You don't have to be unintelligent to believe that you're safer with a gun in your house, or that lower taxes are always better. You just have to be irrational.

What do I mean with irrational? It's a lot of things, but an important element is our common tendency to be more impressed by evidence that supports our worldview, than by evidence that contradicts it.

Let's start with the pistols and revolvers. Of course, it's easy to create in our minds a scenario where you're safer with a gun in your house than without it. "You hear an intruder. You have time to find your gun and load it before the intruder finds it. You know how to use it effectively and responsibly, even when your adrenaline is sky high. The intruder is either unarmed or unprepared." And at the end of the story, you are the hero, unhurt, and the intruder is either dead, wounded or (hopefully just) in chains.

The problem is that this scenario is far more appealing than it is likely. Most people are shot by their own family members or by acquaintances, or by themselves. Not by intruders. If you let objective statistics, and not your wishful thinking be your guide, you'll know that having a gun in your house is far more likely to get you or one of your loved ones shot, than to protect them from getting shot.

As for the taxes, of course it's tempting to believe that we get richer, the more of "our" earnings we're allowed to keep. If you let objective statistics be your guide, however, you'll see that the easiest way to get richer is to live in a rich society, and that rich societies on average have higher tax rates. This doesn't prove that higher taxes will make you rich, but it does suggest, at least to me, that that it's pure wishful thinking to imagine that "my" earnings are "mine", and to forget that the opportunity to make so much wasn't a free lunch.

If you sort the lists of countries by GDP (adjusted for purchasing power) and tax rates (as percentages of GDP), the poorest 25 have an average tax rate of 13,6%, and the richest 25 have 37,2%. Coincidence? Hardly.

History is awash with politicians idealists: People whose grandiose, but irrational beliefs caught on with the masses, and ended up creating major disasters. Marx? Lenin? Hitler? I believe that they all belonged to that category.

If you want to comment on this thread, please let the thread be one of dialogue ("yes, and......"), not debate ("no, because...."). One question I'd like your opinions on, is who the 3 most popular politicians or political movements today are, that stand out by the irrationality of their beliefs?

:-J



Top 25 countries by GDP (adjusted by purchasing power)

GDP Tax Country GDP Tax as % of GDP
rank rank
1 151 Luxemb. 57.640 36,40
2 172 Norway 56.050 43,60
3 47 Singap. 49.850 13,00
4 126 USA 46.730 28,20
5 163 Netherl. 40.510 39,50
6 177 Sweden 38.560 49,70
7 170 Austria 38.550 43,40
8 133 Australia 38.210 30,50
9 150 Denmark 37.720 50,00
10 139 Canada 37.590 33,40
11 161 UK 37.360 39,00
12 99 Germany 36.960 40,60
13 175 Belgium 36.520 46,80
14 100 Finland 34.430 43,60
15 171 France 33.980 46,10
16 165 Iceland 33.390 40,40
17 144 Ireland 33.280 34,00
17 122 Japan 33.280 27,40
19 158 Spain 31.630 37,30
20 168 Italy 31.330 42,60
21 93 Greece 28.440 33,50
22 117 Korea S 27.310 26,80
23 154 Israel 27.040 36,80
24 162 Slovenia 26.340 39,30
25 124 Trin.&Tob. 25.100 28,00
26 153 Czech R. 23.610 36,30
27 156 Portugal 22.870 37,00
28 129 Slovakia 21.600 29,50


Bottom 25 countries by GDP

GDP Tax Country GDP Tax as % of GDP
rank rank
156 50 Liberia 290 13,20
155 40 Congo,DR 300 13,20
154 75 Burundi 390 17,40
153 35 Niger 660 11,00
152 19 C.African R 750 7,70
151 92 Malawi 760 20,70
150 27 S.Leone 790 10,50
149 68 Togo 850 15,50
148 52 Mozamb. 880 13,40
147 134 Ethiopia 930 11,60
146 56 Rwanda 1.060 14,10
145 36 Burkina F. 1.170 11,50
144 33 Nepal 1.180 10,90
142 63 Mali 1.190 15,30
142 45 Uganda 1.190 12,60
141 8 Chad 1.230 4,20
140 71 Zambia 1.280 16,10
139 106 Comoros 1.300 12,00
138 26 Gambiae 1.330 18,90
137 42 Tanzania 1.350 12,00
136 166 Ghana 1.480 20,80
135 65 Benin 1.510 15,40
134 83 Kenya 1.570 18,40
133 22 Banglad. 1.580 8,50
132 54 Côte d'Ivoire 1.640 15,30

Source: Wikipedia
Selection: Countries with data in both columns