In an age in which many teens and young adults seem to equate criticism and not getting what they want with disrespect, it should not be surprising that some argue for unconditional positive regard in education and elsewhere. However, criticism is essential to gaining knowledge.

I am sure that most people have not thought much about why it’s called “critical thinking” and, when asked, would probably assume that “critical” refers to its importance (especially skeptics). However, they would only be partially correct. “Critical” means “crucial”, but it also refers to discriminating judgments. Critical thinking is a process in which we distinguish accurate information from inaccurate information and/or determine the best course of action given a set of possibilities.

The reason criticism is so important is a bit abstract, but it can be at least partially illustrated through the principle of falsification. Essentially, attempting to falsify a hypothesis is the best way to determine if it is likely to be true.

Most skeptics are familiar with the confirmation bias, which is the very strong human tendency to favor confirming information. We notice, remember, believe, and assign more weight to information that confirms what we already believe to be true than other information. What is discussed less often is how this bias extends to how we seek knowledge and test hypotheses. Humans tend to experiment to determine relationships in the world, but we do so in a confirmatory manner when a better approach is to attempt to falsify. That is, we tend to try this or try that to see what happens. However, the best test of a hypothesis is one in which the outcome tells us what is likely to be true by eliminating other possibilities. This is how science works most of the time and I think that we can agree that science works better than any other method.

A good illustration of this human tendency is the Wason 4-Card Task. Fortunately, it is also a good way to explain why falsification is ideal.

In the Wason 4-Card Task (A.K.A. the Wason Selection Task), participants are given the following problem:

There are four cards in front of you, each with a letter on one side and a number on the other side. The rule is: If there is a vowel on one side of a card, then there must be an even number on the other side.

Which cards must be turned over to determine if the rule holds true? (How many cards, minimum, and which ones?) 

The most popular answers in this task are the E and 4 cards or just the E card. This demonstrates an approach to hypothesis testing which is confirmatory in nature. That is, we search for examples of the first condition, then confirm that the second condition is met. This is similar to how most people deal with other types of questions, such as whether or not a pill reduces headache pain. How would you find out? Should you take the pill when you have headache pain, then judge the pill effective if the pain is gone an hour later?

Unfortunately, this approach is not a very effective means of gaining knowledge. To understand why, let’s look at what we can learn from turning over each card.

Only the bold information tells us anything about whether the rule holds true or not and only in the cases in which it is violated do we learn something meaningful enough to draw a conclusion. The correct answer to the basic Wason Task is that both the E and 7 cards are required. The E card can confirm the rule, but what is important is that it, and the 7 card, have the ability to falsify it. Turning over the 4 card is unnecessary because the rule does not even apply unless it has been followed, therefore, we learn nothing interesting.

If my statement about is confusing, you are not alone. This task is one of the most well-studied in the field of cognitive psychology, yet why humans are so bad at it is still a bit of a mystery. One of the hypotheses is that people have a difficult time recognizing that the rule is not bi-directional. In other words, the rule is:

If there is a vowel on one side, there is an even number on the other side.

it is NOT:

If there is a vowel on one side, there is an even number on the other side and vice-versa.

However, when conditional statements like this are made, we often assume that they are bi-directional unless we have context which tells us otherwise. For example, rules like these provide context which suggests more than what is stated:

If it is Monday, then the banks are open.

If I buy a ticket, I will win something in the raffle.

Because we have schemas that tell us that banks are open on weekdays (at least), we understand that the reverse of the first conditional (If the banks are open, then it is Monday) is not necessarily true. In the second conditional, our knowledge of how raffles work tells us that a raffle ticket must have been purchased if the author won something in it. In each case, however, we are not evaluating the statements on their own merit. We introduce information from our knowledge base. The problem with this kind of reasoning is that we assume that our knowledge is accurate.

When these statements are included in arguments, we draw conclusions based, at least in part, on our current understanding of the world, which could be wrong.

One example that I often used in class illustrates how strong this bias can be and how it affects our ability to determine cause and effect relationships. Given the following argument, students are asked to judge whether the argument is valid or invalid. They are reminded that “valid” refers only to whether the argument is logically sound and not whether the statements within it are true (truth is a separate property):

Major Premise: If I learn a lot, I will get a good grade on the test. 

Minor Premise: I got a good grade on the test.

Conclusion: Therefore, I learned a lot. 

On its surface, the argument appears valid. However, it is not. There is nothing in the major premise to indicate that learning is the only way to get a good grade on the test – that learning is required for a good grade. It merely states that learning will guarantee one. Unfortunately, some dedicated students who have successfully used flash cards and other rehearsal techniques in courses in which memorization is helpful – introductory courses with multiple-choice exams and so forth – will assume that this method of studying equates to learning. When they fail in a more rigorous upper-division course in which conceptual understanding is necessary, they will be unlikely to attribute that failure to their study methods.

Going back to the example of how to determine if a pill takes away your headache pain, the method most people follow is to turn over the E card and nothing else. If your headache pain does not go away (outcome: an odd number), then you will know that the pill doesn’t work. However, what if the headache does go away? Is it possible that headaches go away on their own? Could taking the pill induce a placebo effect? What you need is to design an experiment in which you can eliminate all other possibilities (headaches go away by themselves, placebo effects, etc.). What you need to do is set the pill up to fail. If the headache goes away when it should (turning over the E card and finding an even number) AND it does not go away when it should not (turning over the 7 card and finding a consonant), then we can conclude that the pill worked.

The confirmational approach is like asking a psychic to predict the flip of a coin, but only counting the times in which the psychic was correct. This is an excellent way to find out if they have supernatural powers, but only if you also know the rate at which they are incorrect. When skeptics test psychics, they compare the outcome to what would be expected by chance. If they can consistently outperform blind guessing, the only logical conclusion is that they must not be guessing. To eliminate alternative explanations, skeptics ensure that the psychic is not receiving information from other sources such as body language cues.

Now, what does all of this have to do with criticism?

What science does, both in single studies and as a general process, is eliminate incorrect hypotheses. In general, scientists come up with likely hypotheses and theories based on what we are reasonably certain is true (as many as humanly possible), then eliminate them until only one remains. We eliminate them by finding faults with them, by demonstrating that they can’t be true (or are highly unlikely to be true).

Critical thinking works this way, too. The most effective process of evaluating information is one which looks for faults, inconsistencies, and weaknesses. Applying critical thinking to plans and ideas, otherwise we waste resources and time as well as risk harm. After we have completed a project, even a successful one, analysis should not focus on “what we did right”. We can’t know why we succeeded without comparisons to similar situations in which we failed. Focusing on what we think is good is like counting the “hits” and ignoring the “misses”.

In the spring of 2009, one of my brainy students caught me in the hallway before class and pleaded, “Would you please give me something to tell these nutty people to calm down?”

After a few seconds I realized what she was dealing with and asked, “The Aporkalypse?”

Of course we were talking about the H1N1 scare which, at the time, was still called “swine flu”.

When I explained that, no, I couldn’t give her anything because we simply didn’t know enough, she said, “But these people are buying boxes full of hand sanitizer!”

Now, that I could help her with. There is literature addressing the ability of hand sanitizer to prevent illness, but we simply did not know enough about this new strain of virus to predict what would happen.

Nevertheless, most people jumped to conclusions. Those who did not panic summarily dismissed the issue. This kind of thing recyles itself often (climate change, economics, etc.) and other issues, such as scientific illiteracy, mask the more basic phenomenon: We don’t like uncertainty, so we tend to make decisions about what is true with the information we have, even if that information is insufficient.

This is particularly problematic for skeptics who, once they become fired up about a topic, are often blinded by their passions. Of course, this is true for all of us, but since I spend a lot of my time with skeptics, my anecdotes are about them.

For example, in May of last year, I was a little surprised about the reaction, especially of PZ Myers to this court ruling reported by The Orange County Register:

James Corbett, a 20-year teacher at Capistrano Valley High School, was found guilty of referring to Creationism as “religious, superstitious nonsense” during a 2007 classroom lecture, denigrating his former Advanced Placement European history student, Chad Farnan.

The reader comments are more of the same polarized complaints of pursecution that I have come to expect from Pharyngula, but there are a few voices of reason.

If this is not the first time you have read this blog, you might wonder why I am not upset by this ruling myself. I am not upset because I actually read the ruling and it seems obvious to me that the ruling itself is a win for science education.

If you read the original complaint, you will discover that this was a public high school history teacher whose mocking of religion during lectures would put PZ to shame, yet comments such as “When you put on your Jesus glasses, you can’t see the truth” were ruled as having a pedagogical, secular purpose. In fact, a very long list of clearly derogatory comments (some of which are quoted here) were fine, but this single comment was ruled as having no secular purpose because it was made outside the context of the classroom in his role as an advisor for the school newspaper.

Ed Brayton covers this pretty well, I think, in two posts on the matter.

I bring up this example because the reactions on Facebook and other blogs were much like PZ’s knee-jerk, “How can this happen!” and I think that many people would have a completely different perspective if they took a few minutes to get some facts.

I now realize that it is highly likely that PZ’s reaction would be the same, however, and should have know that at the time, given his last paragraph:

Thirdly, and this must be said, Chad Farnan [the high school student who filed the law suit] is a self-righteously moronic creationist wanker who deserves to have his stupidity pointed out publicly, in the classroom and out of it, far and wide. Spread the word.

Where am I going with this?

Earlier this week, California health authorities released a statement declaring an epidemic of whooping cough which has killed 5 babies already this year. There were several articles including New York Times and Consumer Reports.

Being particularly sensitive to antivaccination propaganda and remembering Dana McCaffery, I was immediately interested and read several articles. I could find nothing to indicate that refusals to vaccinate were the primary culprit.

Then I saw a link to an article on my Facebook feed and these were the first few comments:

“Thanks, Jenny.”

The next post was a link titled “Jenny McCarthy kills another five infants in California.”

*sigh*

I am as anti-anti-vax as they come, but I find it distressing when my side sounds like the other side. I felt much as I do when a pharmaceutical company commits fraud.

The comment about ignorance is particularly troubling, since the commenter is ignorant themselves – ignorant of the fact that Whooping Cough did not simply “appear” anywhere. Vaccinations have done a lot to eradicate diseases like small pox, but Whooping Cough has never been close to being stamped out.

I wondered if anyone actually read the article, because there was nothing in it about vaccine fear.

There are many, many sources to blame for the increases, and vaccinations are certainly the best approach we have to stop the spread of infectious disease, but fear of vaccinations is not likely to be among the most important factors in undervaccination in this case. In 2005, the year of the last abnormal outbreak, research showed that it was not even a significant factor:

Studies have yet to show any obvious reason for the increases. No significant outbreaks have been traced to the children of parents who oppose childhood vaccination. “We’ve looked, and we can’t see any obvious connection,” Woodfill said.

There are many things which much be taken into account in this case, including (some of this information is included in the same 2005 article quoted above):

• Outbreaks of pertussis (Whooping Cough) are cyclical and spikes are normal. As we all know from climate change research, data points and bits are often misleading. “Four times as many cases as last year” is very scary, but it is taken out of context.
• The rate of pertussis has been increasing since at least the 1980s. This may or may not be a “true” increase because diagnosis for pertussis has improved with the availability of a better test in 1995 and with better awareness. Many feel that pertussis was likely to have been underdiagnosed in the past because the symptoms (especially in adults) are similar to bronchitis or flu.
• Immunity often fades without boosters, something we have not known until fairly recently. Pregnant women are often tested for antibodies to some diseases (I discovered I needed to be re-innoculated for Rubella myself when I was pregnant with my first child), but most adults don’t bother with vaccines because they think their childhood vaccines were sufficient.
• A booster is recommended for children entering middle school and many states require it for school, but not California.
• California has a large population of immigrants. The 5 children who died were latino. The areas with the highest numbers of cases are areas with large segments of migrant farm workers – poor and uneducated, with little access to quality health care. Although vaccines are free to children on Medical and through other programs, how are parents to know that these vaccines are needed if they do not have proper preventative care? How will they know where or how to receive them?
  Furthermore, many of these immigrants are undocumented. The are unlikely to seek these services or information if they are afraid of deportation.

A few articles, particularly in newspapers for affluent counties like Marin, have cited vaccine refusal as the culprit. They may be correct, but in each case their evidence was the hunch of a single doctor they interviewed. That’s just not enough evidence for a reasonable skeptic.

My point here is not that anti-vaccination propaganda is acceptable. My point is that this issue is complicated, and knee-jerk reactions without even taking the time to read the the information on which one is commenting are irresponsible and damaging.

I left a comment on that thread and the first response was disheartening:

Ok. So the article doesn’t represent the world JMcC has made, but rather the one she wants. Abortion clinic bombings aren’t universal either, but I’m still comfortable using a bit of hyperbole when telling Focus on the Family to fuck off. It’s hard to fit entire position papers into FB threads, and “Immigration Body Count” would be a bit of a red herring.

First, I do not believe that Jenny McCarthy wants children to die. I have no problem calling her a moron as I have in the past. People who have had the truth explained to them as often and as simply as she has and still insist on moving forward with their deadly campaign have earned that much. However, ignorance, arrogance, and incompetence are not wishing children dead, nor is it a reason to wish someone dead as one of the other commenters did.

But what really strikes me is the odd reference to a red herring which is backwards. There is no “hyperbole” here and going off on Jenny McCarthy in reaction to this announcement is a bit like shooting someone for dropping their cigarette butt into the lake while watching a barge dump 3 tons of trash into it 50 yards away.

This is a fallacy of relevance and it chips away at the credibility of anyone who tries to argue that such propaganda is harmful.

Not long after reading this, I saw a link to Bad Astronomy. It is a passionate and certainly heart felt tyrade over the anti-vaccination efforts of people like Jenny McCarthy and Meryl Dorey, but it starts with a discussion of the Whooping Cough epidemic as its title suggests. Phil is one of the more rational among well-known skeptics and I expected more from him.

So I left a comment.

Phil did reply to my comment, and at some point he added a caveat to his post. I do not generally reread posts unless asked, but part of his reply did not sit well with me. In fact, it angered me.

But it’s also true the movement has been making footholds all over the country, and I will take opportunities to point that out when I can.

I felt dismissed, and my anger is clearly reflected in my response:

Defensive much?

By this logic, I should write nice long rant about subtle sexism every time women only make up 20% of a company’s employee list, regardless of how many women applied for those jobs.

And have you thought about what this does to your credibility? To our credibility?

Yes, the anti-vax movement SUCKS. But I’ll repeat what I said because I think it’s important enough to say again: knee-jerk reactions don’t help.

Neither does a defensive response when someone points out that you may have reacted emotionally rather than rationally. You’re human. People will actually admire you more if you admit that.

Just sayin’.

He rebutted that I had overreacted.

Knowing how Phil feels about this topic, I believe quite strongly that, if the shoe were on the other foot, he would have lectured me on the seriousness of the matter. Crying wolf while the sheep are dying of starvation does more than harm Little Boy Blue’s credibility. It prompts people to devote resources to a wolf hunt which are better spent feeding the sheep.

And he would be right to do so. How can we call these people ignorant if we knowingly incite others to make statements of ignorance, like “The disease is making a come-back” and “Thanks, Jenny”? … and if we never correct them? or ourselves?

If I had spent a little more time editing, I probably would have left out the two words of sarcasm, but I cannot say for certain that I would. I am a little person with fewer than 100 readers and I felt slapped down for criticizing someone with millions who is hero-worshipped by most of the community. If you doubt his reach, try Googling “Bad Astronomy” sometime. It took every ounce of courage I have to post a comment in the first place, knowing that many people I consider friends would not take kindly to their friend being criticized.

I felt that this issue is extremely important and it is one of many examples in which passion and polarization get in the way rational thinking. Perhaps another is the double-standards we apply to so many situations.

Just as none of us are completely free of sacred cows, none of us are completely objective. And none of us are perfect, either. For my part, I promise that my intent is always to be the best person that I can be; it is never my intent to be mean unless I (or a friend) am under attack.

I also promise that I will insult people. Sometimes that will be intentional. Sometimes it will be because I was thoughtless and insensitive. Most of the time, however, it will either be my own knee-jerk reaction to feeling dismissed, ignored, or slighted. Every time it will be me being me, for better or for worse.

I think I would rather be disliked for being honest with a touch of sarcasm than be liked for having nothing except praise. The latter also means that I have little which is constructive to say.