The popular press is designed to be popular and often dramatizes or overgeneralizes research findings. Critical thinkers are aware that the popular press is a biased source of information. A critical thinker will view a single report linking urine drinking and improved health with skepticism. A critical thinker will not rely on a newspaper writer’s assessment of research (or even the researcher’s assessment) but will assess the research for himself or herself.
The Critical Thinking Process
1 Ask questions: What makes people happy?
2 Define the problem: What does happy mean? How will you know whether someone is or is not happy?
3 Examine the available evidence: Accepting a conclusion without evidence is not critical thinking.
4 Analyze assumptions and biases: Consider an advertiser who claims that medical doctors prefer her pain reliever. The conclusion she wants you to draw is that doctors prefer her pain reliever because it is a better product. But neither does she say that, nor is it likely to be true. Perhaps doctors prefer it because it is cheaper than other pain relievers. What if the advertiser says that no other pain reliever relieves pain better than hers? What does this really mean? It may mean that her pain reliever is as effective as every other pain reliever on the market. Again, remember the adage Consider the source. The advertiser has an interest in persuading you that her product is better, doesn’t she?
5 Avoid emotional reasoning: Feelings alone are not reliable guides to truth. Set feelings aside as you consider the evidence. Your feeling that something is true does not make it so.
6 Do not oversimplify: One dishonest used-car salesperson does not mean that all used-car salespeople are dishonest—at least we do not think so!
7 Consider other interpretations: In general, a critical thinker accepts the interpretation that accounts for the most evidence with the least number of assumptions. Consider the claim that interpersonal attraction occurs when the planets are aligned. This interpretation requires many assumptions about the nature of the relationship between planetary alignment and human behavior. A better interpretation of attraction might be that people like people who are similar to them.
8 Tolerate uncertainty: Psychologists know that there may be no good answer. A critical thinker knows this and is willing to accept this uncomfortable situation.
Consider a claim that we have heard many times:
“Eating raw oysters increases libido.”
First, let’s consider the possible sources of this popular belief. Perhaps someone in authority claimed that oysters increase libido. Perhaps this belief has been accepted for so long that it has become part of a general belief system (tradition). Perhaps we have had personal experience with eating oysters and the consequences thereof. Perhaps. But we think it is highly unlikely that this belief has come about as a result of scientific inquiry.
So let’s analyze this claim as a critical thinker might.
1 Ask the question: Does eating raw oysters improve libido?
2 Define the problem: How many raw oysters must we eat? How do we measure improved libido?
3 Examine the available evidence: Is there any scientific empirical evidence about oysters and libido?
4 Analyze assumptions and biases: Did the claim originate from oyster farmers?
5 Avoid emotional reasoning: Set aside our feelings about oysters.
6 Don’t oversimplify: Did we have one experience with increased libido after eating some oysters?
7 Consider other interpretations: If we have found that there is evidence that libido increases after eating oysters, could there be another explanation for this? Perhaps we only have the opportunity to eat raw oysters at fancy restaurants with candlelight and romantic settings.
All good scientists practice critical thinking and base their scientific beliefs primarily on empirical evidence. Let’s now turn to the goals or objectives of science.
Objectives of Science
The goals of science are to describe, explain, predict, and control some event(s). A young science first must describe its subject matter. This is the first step, and empiricism is the primary method of doing this. A mature science may be busier with prediction and control. Early astronomers, for example, spent their time describing what they observed in the skies. Only later, when a body of empirical evidence had been gathered, could they begin to explain how planets, stars, and other cosmic entities were formed, interacted, and died.
To Describe
Description of its subject matter is the first objective of a science. The subject matter of psychology is human behavior and mental processes. Describing general laws of human behavior is the work of many researchers in psychology today. Sometimes animal models are used to study human behavior. For example, Frank Epling (deceased) and David Pierce of the University of Alberta have spent several years studying anorexia nervosa in laboratory rats. They have described the phenomenon quite clearly. Rats will develop anorexia if they are given access to a running wheel and if they are given an adequate amount of food for a specific period of time each day. The rats will, over time, spend excessive amounts of time running and will eat less and less, even when adequate food is available, but only when that food is offered for a limited time each day. Are rats the same as humans? Of course not, but this kind of research may offer some insights into similar processes in humans.
To Explain
Once we have described the general laws of our subject matter, we then proceed to try to explain those trends. Epling and Pierce postulated that excessive exercise prompts the body to produce a lot of beta endorphins, which suppress appetite and cause feelings of well-being, sometimes called the runner’s high. This, then, was their explanation for why rats become anorectic under their laboratory conditions. This may not help us explain the problem with humans; humans suffering from anorexia and bulimia have lower levels of beta endorphins.
To Predict
Once a behavior has been well described and an explanation has been offered, the next step is often to make predictions from the explanation. If the predictions are not confirmed, the explanation is considered faulty and must be revised. A prediction that might be made from Epling and Pierce’s explanation for the development of anorexia in rats would be that people with anorexia engage in excessive exercise. Epling and Pierce found that excessive physical exercise in anorectic patients was reported quite often and was thought by professionals to be a side effect of the disorder (Epling & Pierce, 1992). Another interesting prediction Epling and Pierce made was that people in some professions would be more likely than others to become anorectic. For example, according to their model, ballet dancers (who are required to be very active) should be more likely to develop anorexia than models. Both groups must control their weight to be successful, but only ballet dancers must also be active. Epling and Pierce (1992) report that the available data support this prediction.
To Control
Once a science has described, explained, and made predictions about its subject matter, control of the phenomena can be attempted. Applied psychology has a mandate to take the principles of behavior demonstrated by researchers and use them to help with problems people have. For example, a useful control application based on Epling and Pierce’s work might be to treat people with anorexia by reducing the amount of exercise they are getting, rather than trying to change their eating habits.
We have seen that scientists are critical thinkers, their beliefs are founded on empirical evidence, and their goals in doing their