What Ever Happened to Critical Thinking?

In the world where “opinions” travel through the Internet at light speed often presented as “facts”, how do you know what you can believe? If there is a single skill that is necessary for day to day living it’s being able to think critically. That is, being able to separate the silly from the factual, the rational from the irrational, and the biased from the unbiased. Of all the skills taught in schools, critical thinking never takes front stage. Thus, sooner rather than later, you’re on your own to think, or to try and think, critically.

Here Is a Common Example:

Say an advertisement says their product cleans better than “the leading competitor” by 500%. Of course, 500% sounds big, but 500% just means five times “something”. If the “something” is small to begin with, then five times that amount may not be significantly greater. So, when an advertisement says that a product cleans 500% better than the “leading competitor”, some of the questions that might come to mind include:

- Was there any serious investigation done at all or is this ad just a silly claim?

- Is that cleaning increase significant? What if the leading competitor’s cleaning metric is only 0.00034. Then five times that number is only 0.0017. Significant? Should I care?

- What does “better” mean in this context?

- Who is the leading competitor?

- 500% of “what” (objectively-obtained) cleaning metric?

- How did the investigators measure this claimed cleaning improvement?

- Can I trust the numbers from this source (the advertiser itself)?

- What kind of data were gathered? Nominal, ratio, etc?

- Were the cleaning tests done objectively or subjectively by (possibly paid by company) human “evaluators”?

- How many cleaning trials did the company do?

- What kind of lighting did the investigators use to view/measure cleaning differences?

- How did the company make comparisons to the “leading competitor”?

- Did the company use statistical methods? If so, which ones? At what significance level? With what assumptions? (where can I find those analyses data?)

- What types of clothes did the company use for comparisons (all white cotton clothing or clothing with colors more difficult to judge cleanliness differences between products)?

- What types of stains (dirt, oil, etc.) did the company use?

- Does the company have a “celebrity spokesperson”? Almost always, a celebrity endorser is a red flag. Logically speaking, a celebrity endorsor is: “The Fallacy of the Irrelevant Authority”. Of course, a celebrity endorser who is paid just to endorse the product doesn’t mean the product doesn’t work. In any case, since the celebrity endorsor rarely knows anything about the product he or she is endorsing, a celebrity endorsor demonstrates persuasion via personality - not logic.

With these critical questions, and others you might think of, you’ll be in a better position not to have, in this case, advertising, sway you with their (often unsubstantiated) messages.

From the critical questions above, we can generalize to say that good general critical thinking skills include:

  • Curiosity - Wanting to learn more information about things around us.
  • Skepticism - Not always believing, without investigation, and not blindly accepting what we hear.
  • Objective Research Methods - Objective methods to test hypotheses. Verify data. Repeat results. Break a large problem into smaller ones if necessary.
  • Humility- The ability to rationally admit we were wrong about a belief or idea.
  • Thinking logically not emotionally

Example of Critical Thinking in Action:

When researchers start an experiment, they often have a belief on what the outcome will be. Yet, if the objective experiment’s results don’t match those pre-conceptions a researcher had, the researcher accepts the results.

Stop! You’re Not Making Sense to Begin With!

Be wary of claims where the claim itself makes no sense to begin with. If a claim says that something is 2 times smaller, or takes 4 times less time, you need to clarify that claim’s hypothesis. Since “1 times” = 100%, you can’t exceed that amount for something that’s less than 100% in some dimension (time, space, etc.). In other words, it’s impossible that something can be 2 times smaller or take 300% less time. (a measurement could be one-half as large, but not twice as small.) With imprecisely or incorrectly (or mathematically impossible) stated claims, you might correctly conclude that the claims themselves need serious investigation or clarification (and doubt).

Secondary Data

The additional problem we have is that all of the data we get is (at best) secondary data. That is, since we didn’t get the data ourselves, we have to believe (or somehow verify) that the data we got are accurate. Thus, we need to know who got the data, what their agendas might be, if any, and so on. Can we dismiss diet claims from diet company commercials? Well, show us the data! How was the data gathered? By whom? Etc. (Having a healthy diet and exercise and avoiding diets - in the first place - would be recommended, but never mentioned on these commercials.).


Thinking critically is the a critical skill you need to have your entire life. You may never need to use Avogadro’s number or solve a differential equation, but critical thinking is something you can use every day to separate the silly from the factual, the rational from the irrational, and the biased from the unbiased.


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