Monday, June 4, 2012

Why don’t we believe science? – an empirical point of view.

A quiz:

Let's begin with a quick quiz: 

For each of the statements below,  determine if it was made by a well respected scientist or by a politician: 

1. "Most research findings are wrong" 
2. "The science is bad". 
3. "Some proportion of the findings in the literature simply might not replicate".

Disbelief in Science 

We will get to the answers in a bit. But it should be quite shocking if any of the statements above were made by a serious scientist, wouldn't it? Intelligent people should believe in science.
For example, P. Krugman column in the NY times and the Guardian was outraged by the fact that  the republican party "is becoming the 'anti-science party.' This is an enormously important development. And it should terrify us". reported in Feb 2012 summarizes the climate science by saying that: "A stark theme emerged from an annual scientific get-together in Vancouver: the world must be helped to believe in science again or it could be too late to save our planet". 

How come so many do not believe in science? It would be even harder to understand if scientists could make any of the statements in the quiz.

Without science, the industrial and electronic revolutions could not have taken place. 
The life expectancy would have been much lower and most of us would spend most of our time fulfilling the most basic needs instead of having so much recreational time. 

Still many of us instinctively do not believe to statement by scientists. And 2 of statements in the quiz were made by respected scientists. The first statement was made by John P. A. Ioannidis from Stanford in a 2008 paper in PLoS Medecine. The third statement was made by Eric-Jan Wagenmakers from Amsterdam in a recent paper in Nature discussing results published in Journal of Personality and Social Psychology establishing a psi effect. The 2nd statement was made by the republican candidate Tim Pawlenty in 2012.

How come both the general public and leading scientists do not believe in science?

Why is it rational to not believe in science?

I want to suggest a very simple explanation which justifies the disbelief on rational and even scientific grounds.
The first ingredient of the explanation is that science and scientists often present their work in public as indisputable truth. Although there are some careful scientists around, we have all seen scientists talk in great confidence in the media many times before.

The second ingredient is that during our lifetimes scientific theories keep changing, even dramatically.

Here are a few quick examples from the medical world: until very recently we were told that fats are bad for us while carbs are not while now we are told the opposite is true (see Gary Taubes book on "Good Calories Bad Calories")  
Until very recently we were told that what is important for health is to exercise every day or a few times a week while now we are told the most important thing is not to sit for too long (see NPR coverage).
Even more dramatic examples include the strongly advocated radical mastectomy and prostate surgery for treating breast and prostate cancer respectively - we are now told that these aggressive treatments do not help! (for the breast cancer story I recommend the book "the emperor of maladies by Siddhartha Mukherjee) 

In addition to the confidence of scientists and their statements and the fact that scientific theories goes into and out of fashion,  the third ingredient is just common sense:
Scientists tell us that we should believe without doubt well founded scientific theories.
Yet – we all see that theories that a decade or two ago were considered bullet proof are now considered simply wrong. As we saw above in some cases respectable scientists refer in the same way to the majority of the work in their own field. So common sense implies we should not trust scientists! 

The Popper Falsifiability Principle in action

Interestingly the application of the logic above follows basic scientific principles - that is the "Popper Falsifiability Principle". Roughly speaking, the principle states that theories should make predictions that are falsifiable and that we should reject the theories if the predictions are false.
At its extreme, the principle says that a good theory should make many predictions and that if even one prediction is wrong than the theory is wrong. 

In our discussion the theory is that "we should listen to scientists since they know what they are saying" and the predictions are scientific statements.  History demonstrates that theories from the past are now considered dead wrong. As we saw above in some cases respectable scientists refer in the same way to the majority of the current work in their own field!
The public then concludes that we should not listen to scientists since many of their predictions are wrong. 

In other words, applying the Popper principle, people quickly realize that the meta-theory that science that is said to be well founded must be true is just wrong. So there is no need to even consider new scientific theories seriously. 

Note that this logic doesn't contradict the usefulness that the same reasonable people extract from science. They have seen many people fly safely - so they will fly. They have seen and heard of antibiotics successfully fighting infections so they will take antibiotics to fight their own infections. 

What reasonable people do

However, this sound approach to scientific truths is not without problems. While
these individuals have seen antibiotics help, they may not believe what their doctors are saying. So they may insist on taking antibiotics for viral infections. Moreover, they have never seen anyone suffer from any of the diseases for which they are required to vaccinate their children - so why would they take the unknown risk of vaccination? And why would they believe climate scientists when the meteorologists fail so consistently in predicting the weather pattern for next month?  

In other words, while the "reasonable approach" of believing only science that we see working with our own eyes is well founded by the many failures of sciences, it creates enormous problems if policies are to be informed by science. As the number of smokers and lung cancer cases are declining , why should people believe that smoking is bad for them? In a world where many of us sit all day, why should people believe that it's bad for them?  why should people believe that the world is warming up and they should do something about it?

There is a stronger form of belief of science that is needed to believe in immunization or in climate change. However, as we've seen the empirical observation of the dynamic changes in what is "scientifically true" results in the public being skeptic.

I think that much of this can be fixed and that it is up to us scientists to fix it.
In future posts I am planning to investigate these and related questions in more detail by looking at the role of "invisible hand of science" (science evaluation mechanisms), the interaction of science with the public, industry and the government; the roles of replication and critique. I also plan to look at specific branches of science and ask if some are better than others and if 
some branches of science do more harm than good.

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